diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a8e82e2d1..e1ebb7af1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -153,5 +153,5 @@ jobs:
       run: |
         mx --env trufflesqueak-svm build --dependencies GRAALVM_TRUFFLESQUEAK_SVM_JAVA17
         echo "$(mx --env trufflesqueak-svm graalvm-home)/bin" >> $GITHUB_PATH
-    - name: Run Cuis-Smalltalk tests on TruffleSqueak
+    - name: Run Cuis-Smalltalk tests on TruffleSqueak in native mode
       run: trufflesqueak --native --headless --experimental-options --engine.CompilationFailureAction=ExitVM --engine.TreatPerformanceWarningsAsErrors=all images/Cuis6.0-????.image -s src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/runCuisTests.st
diff --git a/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/AbstractSqueakTestCase.java b/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/AbstractSqueakTestCase.java
index cc0556056..8e2b909c6 100644
--- a/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/AbstractSqueakTestCase.java
+++ b/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/AbstractSqueakTestCase.java
@@ -39,11 +39,11 @@ public abstract class AbstractSqueakTestCase {
     protected static SqueakImageContext image;
     protected static PointersObject nilClassBinding;
 
-    protected static CompiledCodeObject makeMethod(final byte[] bytes, final Object[] literals) {
+    protected static final CompiledCodeObject makeMethod(final byte[] bytes, final Object[] literals) {
         return new CompiledCodeObject(image, bytes, literals, image.compiledMethodClass);
     }
 
-    protected static CompiledCodeObject makeMethod(final Object[] literals, final int... intbytes) {
+    protected static final CompiledCodeObject makeMethod(final Object[] literals, final int... intbytes) {
         final byte[] bytes = new byte[intbytes.length + 1];
         for (int i = 0; i < intbytes.length; i++) {
             bytes[i] = (byte) intbytes[i];
@@ -55,15 +55,15 @@ protected static CompiledCodeObject makeMethod(final Object[] literals, final in
         return makeMethod(bytes, literals);
     }
 
-    protected static long makeHeader(final int numArgs, final int numTemps, final int numLiterals, final boolean hasPrimitive, final boolean needsLargeFrame) { // shortcut
+    protected static final long makeHeader(final int numArgs, final int numTemps, final int numLiterals, final boolean hasPrimitive, final boolean needsLargeFrame) { // shortcut
         return CompiledCodeObject.makeHeader(true, numArgs, numTemps, numLiterals, hasPrimitive, needsLargeFrame);
     }
 
-    protected CompiledCodeObject makeMethod(final int... intbytes) {
+    protected static final CompiledCodeObject makeMethod(final int... intbytes) {
         return makeMethod(new Object[]{makeHeader(0, 5, 14, false, true), nilClassBinding}, intbytes);
     }
 
-    protected static Object runMethod(final CompiledCodeObject code, final Object receiver, final Object... arguments) {
+    protected static final Object runMethod(final CompiledCodeObject code, final Object receiver, final Object... arguments) {
         final VirtualFrame frame = createTestFrame(code);
         Object result = null;
         try {
@@ -74,11 +74,11 @@ protected static Object runMethod(final CompiledCodeObject code, final Object re
         return result;
     }
 
-    protected ExecuteTopLevelContextNode createContext(final CompiledCodeObject code, final Object receiver) {
+    protected static final ExecuteTopLevelContextNode createContext(final CompiledCodeObject code, final Object receiver) {
         return createContext(code, receiver, ArrayUtils.EMPTY_ARRAY);
     }
 
-    protected static ExecuteTopLevelContextNode createContext(final CompiledCodeObject code, final Object receiver, final Object[] arguments) {
+    protected static final ExecuteTopLevelContextNode createContext(final CompiledCodeObject code, final Object receiver, final Object[] arguments) {
         final ContextObject testContext = ContextObject.create(image, code.getSqueakContextSize());
         testContext.setReceiver(receiver);
         testContext.setCodeObject(code);
@@ -96,34 +96,34 @@ protected static ExecuteTopLevelContextNode createContext(final CompiledCodeObje
         return ExecuteTopLevelContextNode.create(image, null, testContext, false);
     }
 
-    protected Object runMethod(final Object receiver, final int... intbytes) {
+    protected static final Object runMethod(final Object receiver, final int... intbytes) {
         return runMethod(receiver, new AbstractSqueakObject[0], intbytes);
     }
 
-    protected Object runMethod(final Object receiver, final Object[] arguments, final int... intbytes) {
+    protected static final Object runMethod(final Object receiver, final Object[] arguments, final int... intbytes) {
         final CompiledCodeObject method = makeMethod(intbytes);
         return runMethod(method, receiver, arguments);
     }
 
-    protected Object runBinaryPrimitive(final int primCode, final Object rcvr, final Object... arguments) {
+    protected static final Object runBinaryPrimitive(final int primCode, final Object rcvr, final Object... arguments) {
         return runPrim(new Object[]{17104899L}, primCode, rcvr, arguments);
     }
 
-    protected Object runQuinaryPrimitive(final int primCode, final Object rcvr, final Object... arguments) {
+    protected static final Object runQuinaryPrimitive(final int primCode, final Object rcvr, final Object... arguments) {
         return runPrim(new Object[]{68222979L}, primCode, rcvr, arguments);
     }
 
-    protected Object runPrim(final Object[] literals, final int primCode, final Object rcvr, final Object... arguments) {
+    protected static final Object runPrim(final Object[] literals, final int primCode, final Object rcvr, final Object... arguments) {
         final CompiledCodeObject method = makeMethod(literals, 139, primCode & 0xFF, (primCode & 0xFF00) >> 8);
         return runMethod(method, rcvr, arguments);
     }
 
-    protected static VirtualFrame createTestFrame(final CompiledCodeObject code) {
+    protected static final VirtualFrame createTestFrame(final CompiledCodeObject code) {
         final Object[] arguments = FrameAccess.newWith(code, NilObject.SINGLETON, null, new Object[]{NilObject.SINGLETON});
         return Truffle.getRuntime().createVirtualFrame(arguments, code.getFrameDescriptor());
     }
 
-    protected static SqueakImage loadImageContext(final String imagePath) {
+    protected static final SqueakImage loadImageContext(final String imagePath) {
         assert context == null && image == null;
         final Builder contextBuilder = Context.newBuilder();
         contextBuilder.allowAllAccess(true);
@@ -150,7 +150,7 @@ protected static SqueakImage loadImageContext(final String imagePath) {
         }
     }
 
-    protected static void destroyImageContext() {
+    protected static final void destroyImageContext() {
         // Close context if existing (for reloading mechanism).
         context.close(true);
         context = null;
diff --git a/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/SqueakPrimitiveTest.java b/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/SqueakPrimitiveTest.java
index 123cb6d60..85f666a00 100644
--- a/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/SqueakPrimitiveTest.java
+++ b/src/de.hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/SqueakPrimitiveTest.java
@@ -23,6 +23,7 @@
 import de.hpi.swa.trufflesqueak.model.LargeIntegerObject;
 import de.hpi.swa.trufflesqueak.model.NilObject;
 
+@SuppressWarnings("static-method")
 public final class SqueakPrimitiveTest extends AbstractSqueakTestCaseWithDummyImage {
     @Test
     public void testPrimEquivalent() {
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/exceptions/SqueakExceptions.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/exceptions/SqueakExceptions.java
index da15020b7..6501ab8a7 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/exceptions/SqueakExceptions.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/exceptions/SqueakExceptions.java
@@ -30,6 +30,7 @@
 
 public final class SqueakExceptions {
 
+    @SuppressWarnings("static-method")
     @ExportLibrary(InteropLibrary.class)
     protected abstract static class AbstractSqueakException extends AbstractTruffleException {
         private static final long serialVersionUID = 1L;
@@ -51,17 +52,17 @@ protected AbstractSqueakException(final String message, final Node location) {
 
         @ExportMessage
         @TruffleBoundary
-        protected Object toDisplayString(@SuppressWarnings("unused") final boolean allowSideEffects) {
+        protected final Object toDisplayString(@SuppressWarnings("unused") final boolean allowSideEffects) {
             return toString();
         }
 
         @ExportMessage
-        protected boolean hasLanguage() {
+        protected final boolean hasLanguage() {
             return true;
         }
 
         @ExportMessage
-        protected Class<? extends TruffleLanguage<?>> getLanguage() {
+        protected final Class<? extends TruffleLanguage<?>> getLanguage() {
             return SqueakLanguage.class;
         }
     }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/SqueakLanguageView.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/SqueakLanguageView.java
index 9ef66f696..9ba479741 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/SqueakLanguageView.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/SqueakLanguageView.java
@@ -8,7 +8,6 @@
 
 import static com.oracle.truffle.api.CompilerDirectives.shouldNotReachHere;
 
-import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.TruffleLanguage;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.Cached.Shared;
@@ -84,21 +83,4 @@ private static boolean isPrimitiveOrFromOtherLanguage(final Object value) {
             throw shouldNotReachHere(e);
         }
     }
-
-    @TruffleBoundary
-    public static Object forValue(final Object value) {
-        if (value == null) {
-            return null;
-        }
-        final InteropLibrary lib = InteropLibrary.getFactory().getUncached(value);
-        try {
-            if (lib.hasLanguage(value) && lib.getLanguage(value) == SqueakLanguage.class) {
-                return value;
-            } else {
-                return create(value);
-            }
-        } catch (final UnsupportedMessageException e) {
-            throw shouldNotReachHere(e);
-        }
-    }
 }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/WrapToSqueakNode.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/WrapToSqueakNode.java
index b48aaa800..55ab83325 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/WrapToSqueakNode.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/interop/WrapToSqueakNode.java
@@ -41,10 +41,6 @@ public final Object[] executeObjects(final Object... values) {
         return wrappedElements;
     }
 
-    public final ArrayObject executeList(final Object... values) {
-        return (ArrayObject) executeWrap(values);
-    }
-
     @Specialization
     protected static final boolean doBoolean(final boolean value) {
         return value;
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/ClassObject.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/ClassObject.java
index db58a03e1..7f2e34247 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/ClassObject.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/ClassObject.java
@@ -6,9 +6,7 @@
  */
 package de.hpi.swa.trufflesqueak.model;
 
-import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.List;
 
 import com.oracle.truffle.api.Assumption;
 import com.oracle.truffle.api.CompilerDirectives;
@@ -238,7 +236,7 @@ public boolean isCompiledMethodClass() {
         return this == image.compiledMethodClass;
     }
 
-    public boolean includesBehavior(final ClassObject squeakClass) {
+    private boolean includesBehavior(final ClassObject squeakClass) {
         ClassObject current = this;
         while (current != null) {
             if (current == squeakClass) {
@@ -413,23 +411,6 @@ public CompiledCodeObject lookupMethodInMethodDictSlow(final NativeObject select
         return (CompiledCodeObject) lookupInMethodDictSlow(selector);
     }
 
-    @TruffleBoundary
-    public Object[] listInteropMembers() {
-        final List<String> methodNames = new ArrayList<>();
-        ClassObject lookupClass = this;
-        while (lookupClass != null) {
-            final VariablePointersObject methodDictObject = lookupClass.getMethodDict();
-            final Object[] methodDictVariablePart = methodDictObject.getVariablePart();
-            for (final Object methodSelector : methodDictVariablePart) {
-                if (methodSelector instanceof NativeObject) {
-                    methodNames.add(((NativeObject) methodSelector).asStringUnsafe().replace(':', '_'));
-                }
-            }
-            lookupClass = lookupClass.getSuperclassOrNull();
-        }
-        return methodNames.toArray(new String[0]);
-    }
-
     public int getBasicInstanceSize() {
         return (int) (format & 0xffff);
     }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/CompiledCodeObject.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/CompiledCodeObject.java
index b0f82c5ab..fce14fed3 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/CompiledCodeObject.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/CompiledCodeObject.java
@@ -64,13 +64,13 @@ public final class CompiledCodeObject extends AbstractSqueakObjectWithClassAndHa
      * Literals are cached in the AST and bytes are represented by nodes, so this should not affect
      * performance. Find out why it does affect performance.
      */
-    @CompilationFinal(dimensions = 1) protected Object[] literals;
-    @CompilationFinal(dimensions = 1) protected byte[] bytes;
-    @CompilationFinal protected int numArgs;
-    @CompilationFinal protected int numLiterals;
-    @CompilationFinal protected boolean hasPrimitive;
-    @CompilationFinal protected boolean needsLargeFrame;
-    @CompilationFinal protected int numTemps;
+    @CompilationFinal(dimensions = 1) private Object[] literals;
+    @CompilationFinal(dimensions = 1) private byte[] bytes;
+    @CompilationFinal private int numArgs;
+    @CompilationFinal private int numLiterals;
+    @CompilationFinal private boolean hasPrimitive;
+    @CompilationFinal private boolean needsLargeFrame;
+    @CompilationFinal private int numTemps;
 
     private AbstractSqueakBytecodeDecoder decoder;
 
@@ -103,14 +103,14 @@ public CompiledCodeObject(final SqueakImageContext image, final byte[] bc, final
         bytes = bc;
     }
 
-    protected CompiledCodeObject(final CompiledCodeObject original) {
+    private CompiledCodeObject(final CompiledCodeObject original) {
         super(original);
         frameDescriptor = original.frameDescriptor;
         setLiteralsAndBytes(original.literals.clone(), original.bytes.clone());
         decoder = original.decoder;
     }
 
-    protected CompiledCodeObject(final CompiledCodeObject outerCode, final int startPC) {
+    private CompiledCodeObject(final CompiledCodeObject outerCode, final int startPC) {
         super(outerCode);
         outerCode.shadowBlocks.put(startPC, this);
 
@@ -222,7 +222,7 @@ private void renewCallTarget() {
         initializeCallTargetUnsafe();
     }
 
-    protected void initializeCallTargetUnsafe() {
+    private void initializeCallTargetUnsafe() {
         CompilerAsserts.neverPartOfCompilation();
         final SqueakLanguage language = SqueakImageContext.getSlow().getLanguage();
         final RootNode rootNode;
@@ -322,7 +322,7 @@ public int findLineNumber(final int index) {
         return decoder.findLineNumber(this, index);
     }
 
-    protected void decodeHeader() {
+    private void decodeHeader() {
         CompilerDirectives.transferToInterpreterAndInvalidate();
         final long header = (long) literals[0];
         numLiterals = CompiledCodeHeaderDecoder.getNumLiterals(header);
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/LargeIntegerObject.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/LargeIntegerObject.java
index 63c12f4df..426ff16eb 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/LargeIntegerObject.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/LargeIntegerObject.java
@@ -475,11 +475,6 @@ public int compareTo(final long b) {
         }
     }
 
-    @TruffleBoundary(transferToInterpreterOnException = false)
-    public double doubleValue() {
-        return integer.doubleValue();
-    }
-
     /** {@link BigInteger#signum()} does not need a {@link TruffleBoundary}. */
     public boolean isZero() {
         return integer.signum() == 0;
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/NilObject.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/NilObject.java
index 34d32d280..16733ee08 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/NilObject.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/NilObject.java
@@ -30,10 +30,6 @@ public static Object nullToNil(final Object object) {
         return object == null ? SINGLETON : object;
     }
 
-    public static Object nullToNil(final Object object, final ConditionProfile profile) {
-        return profile.profile(object == null) ? SINGLETON : object;
-    }
-
     @Override
     public long getSqueakHash() {
         return SQUEAK_HASH;
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/layout/SlotLocation.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/layout/SlotLocation.java
index c65592386..d284a72e0 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/layout/SlotLocation.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/layout/SlotLocation.java
@@ -397,7 +397,7 @@ public final void unset(final AbstractPointersObject object) {
         }
     }
 
-    protected static int getPrimitiveUsedMask(final int index) {
+    private static int getPrimitiveUsedMask(final int index) {
         assert 0 <= index && index < Integer.SIZE;
         return 1 << index;
     }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/DoItRootNode.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/DoItRootNode.java
index 642b3b2a4..519992b45 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/DoItRootNode.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/DoItRootNode.java
@@ -16,7 +16,7 @@
 import de.hpi.swa.trufflesqueak.model.NilObject;
 
 public final class DoItRootNode extends RootNode {
-    @Child protected WrapToSqueakNode wrapNode = WrapToSqueakNode.create();
+    @Child private WrapToSqueakNode wrapNode = WrapToSqueakNode.create();
     private final SqueakImageContext image;
     private final Object maybeClosure;
 
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/ExecuteBytecodeNode.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/ExecuteBytecodeNode.java
index a7a1cb111..30bc30dc7 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/ExecuteBytecodeNode.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/ExecuteBytecodeNode.java
@@ -33,7 +33,7 @@
 public final class ExecuteBytecodeNode extends AbstractExecuteContextNode {
     private static final int LOCAL_RETURN_PC = -2;
 
-    protected final CompiledCodeObject code;
+    private final CompiledCodeObject code;
     private final int initialPC;
     private SourceSection section;
 
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/StartContextRootNode.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/StartContextRootNode.java
index ecc80682e..039800b78 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/StartContextRootNode.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/StartContextRootNode.java
@@ -63,7 +63,7 @@ public Object execute(final VirtualFrame frame) {
     }
 
     @ExplodeLoop
-    public void initializeFrame(final VirtualFrame frame) {
+    private void initializeFrame(final VirtualFrame frame) {
         if (writeTempNodes == null) {
             CompilerDirectives.transferToInterpreterAndInvalidate();
             final BlockClosureObject closure = FrameAccess.getClosure(frame);
@@ -88,8 +88,8 @@ public void initializeFrame(final VirtualFrame frame) {
 
         // TODO: avoid nilling out of temp slots to allow slot specializations
         // Initialize remaining temporary variables with nil in newContext.
-        for (int i = 0; i < writeTempNodes.length; i++) {
-            writeTempNodes[i].executeWrite(frame, NilObject.SINGLETON);
+        for (final FrameStackWriteNode node : writeTempNodes) {
+            node.executeWrite(frame, NilObject.SINGLETON);
         }
     }
 
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/accessing/ArrayObjectNodes.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/accessing/ArrayObjectNodes.java
index 78b02cdb6..5a96d65a2 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/accessing/ArrayObjectNodes.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/accessing/ArrayObjectNodes.java
@@ -335,7 +335,7 @@ public static ArrayObjectCopyIntoObjectArrayNode create(final int offset) {
         }
 
         public static ArrayObjectCopyIntoObjectArrayNode createForFrameArguments() {
-            return ArrayObjectCopyIntoObjectArrayNodeGen.create(FrameAccess.getArgumentStartIndex());
+            return create(FrameAccess.getArgumentStartIndex());
         }
 
         public abstract void execute(Object[] target, ArrayObject obj);
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/PushBytecodes.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/PushBytecodes.java
index 1182a0afe..ef4e55d45 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/PushBytecodes.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/PushBytecodes.java
@@ -441,7 +441,7 @@ private static Object getPushValue(final Object literal) {
     }
 
     public static final class PushNewArrayNode extends AbstractPushNode {
-        @Child protected ArrayNode arrayNode;
+        @Child private ArrayNode arrayNode;
 
         protected PushNewArrayNode(final CompiledCodeObject code, final int index, final int numBytecodes, final byte param) {
             super(code, index, numBytecodes);
@@ -469,7 +469,7 @@ public ArrayNode(final int arraySize) {
         }
 
         protected static final class ArrayFromStackNode extends ArrayNode {
-            @Child protected FrameStackPopNNode popNNode;
+            @Child private FrameStackPopNNode popNNode;
 
             public ArrayFromStackNode(final int arraySize) {
                 super(arraySize);
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/ReturnBytecodes.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/ReturnBytecodes.java
index f62f38929..39f88cd79 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/ReturnBytecodes.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/ReturnBytecodes.java
@@ -44,7 +44,7 @@ public final Object executeReturn(final VirtualFrame frame) {
     }
 
     public abstract static class AbstractNormalReturnNode extends AbstractReturnNode {
-        @Child protected AbstractReturnKindNode returnNode;
+        @Child private AbstractReturnKindNode returnNode;
 
         protected AbstractNormalReturnNode(final VirtualFrame frame, final CompiledCodeObject code, final int index) {
             super(code, index);
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/SendBytecodes.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/SendBytecodes.java
index 038d5ff4c..bb794ec2a 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/SendBytecodes.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/bytecodes/SendBytecodes.java
@@ -226,7 +226,7 @@ public NativeObject getSelector() {
             return dispatchNode.getSelector();
         }
 
-        protected Object peekAtReceiver(final VirtualFrame frame) {
+        private Object peekAtReceiver(final VirtualFrame frame) {
             if (peekAtReceiverNode == null) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();
                 final int sp = FrameAccess.getStackPointer(frame);
@@ -235,7 +235,7 @@ protected Object peekAtReceiver(final VirtualFrame frame) {
             return peekAtReceiverNode.executeRead(frame);
         }
 
-        protected ClassObject popDirectedClass(final VirtualFrame frame) {
+        private ClassObject popDirectedClass(final VirtualFrame frame) {
             if (readDirectedClassNode == null) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();
                 /* Decrement sp to pop directed class. */
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/dispatch/LookupClassGuard.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/dispatch/LookupClassGuard.java
index a90d458b2..7fb784ce4 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/dispatch/LookupClassGuard.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/dispatch/LookupClassGuard.java
@@ -65,9 +65,6 @@ public static LookupClassGuard create(final Object receiver) {
     private static final class NilGuard extends LookupClassGuard {
         private static final NilGuard SINGLETON = new NilGuard();
 
-        private NilGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver == NilObject.SINGLETON;
@@ -82,9 +79,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class TrueGuard extends LookupClassGuard {
         private static final TrueGuard SINGLETON = new TrueGuard();
 
-        private TrueGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver == Boolean.TRUE;
@@ -99,9 +93,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class FalseGuard extends LookupClassGuard {
         private static final FalseGuard SINGLETON = new FalseGuard();
 
-        private FalseGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver == Boolean.FALSE;
@@ -116,9 +107,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class SmallIntegerGuard extends LookupClassGuard {
         private static final SmallIntegerGuard SINGLETON = new SmallIntegerGuard();
 
-        private SmallIntegerGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver instanceof Long;
@@ -133,9 +121,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class CharacterGuard extends LookupClassGuard {
         private static final CharacterGuard SINGLETON = new CharacterGuard();
 
-        private CharacterGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver instanceof Character || receiver instanceof CharacterObject;
@@ -150,9 +135,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class DoubleGuard extends LookupClassGuard {
         private static final DoubleGuard SINGLETON = new DoubleGuard();
 
-        private DoubleGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver instanceof Double;
@@ -167,9 +149,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class ContextObjectGuard extends LookupClassGuard {
         private static final ContextObjectGuard SINGLETON = new ContextObjectGuard();
 
-        private ContextObjectGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver instanceof ContextObject;
@@ -184,9 +163,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class FloatObjectGuard extends LookupClassGuard {
         private static final ForeignObjectGuard SINGLETON = new ForeignObjectGuard();
 
-        private FloatObjectGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return receiver instanceof FloatObject;
@@ -247,9 +223,6 @@ protected ClassObject getSqueakClassInternal(final SqueakImageContext image) {
     private static final class ForeignObjectGuard extends LookupClassGuard {
         private static final ForeignObjectGuard SINGLETON = new ForeignObjectGuard();
 
-        private ForeignObjectGuard() {
-        }
-
         @Override
         protected boolean check(final Object receiver) {
             return !SqueakGuards.isAbstractSqueakObject(receiver) && !SqueakGuards.isUsedJavaPrimitive(receiver);
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/interrupts/CheckForInterruptsState.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/interrupts/CheckForInterruptsState.java
index a59550e84..858b070af 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/interrupts/CheckForInterruptsState.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/interrupts/CheckForInterruptsState.java
@@ -176,7 +176,7 @@ public boolean shouldTriggerNoTimer() {
         return shouldTriggerNoTimer;
     }
 
-    public void resetTriggers() {
+    private void resetTriggers() {
         shouldTrigger = false;
         shouldTriggerNoTimer = false;
     }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/plugins/UnixOSProcessPlugin.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/plugins/UnixOSProcessPlugin.java
index 73921acde..db637ce95 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/plugins/UnixOSProcessPlugin.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/plugins/UnixOSProcessPlugin.java
@@ -529,7 +529,7 @@ protected final String getFunctionName() {
         }
 
         @Override
-        protected String getFunctionSignature() {
+        protected final String getFunctionSignature() {
             return "(SINT32,SINT32):SINT32";
         }
     }
@@ -549,7 +549,7 @@ protected final String getFunctionName() {
         }
 
         @Override
-        protected String getFunctionSignature() {
+        protected final String getFunctionSignature() {
             return "(SINT32,SINT32):SINT32";
         }
     }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/ArithmeticPrimitives.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/ArithmeticPrimitives.java
index 913f1df59..fdb183456 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/ArithmeticPrimitives.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/ArithmeticPrimitives.java
@@ -280,12 +280,12 @@ protected static final Object doLongDouble(final long lhs, final double rhs,
     @SqueakPrimitive(indices = 10)
     protected abstract static class PrimDivideNode extends AbstractArithmeticPrimitiveNode implements BinaryPrimitiveFallback {
         @Specialization(guards = {"rhs != 0", "!isOverflowDivision(lhs, rhs)", "isIntegralWhenDividedBy(lhs, rhs)"})
-        public static final long doLong(final long lhs, final long rhs) {
+        protected static final long doLong(final long lhs, final long rhs) {
             return lhs / rhs;
         }
 
         @Specialization(guards = {"rhs != 0", "!isOverflowDivision(lhs, rhs)"}, replaces = "doLong")
-        public final Object doLongFraction(final long lhs, final long rhs,
+        protected final Object doLongFraction(final long lhs, final long rhs,
                         @Cached final ConditionProfile fractionProfile,
                         @Cached final AbstractPointersObjectWriteNode writeNode) {
             if (fractionProfile.profile(SqueakGuards.isIntegralWhenDividedBy(lhs, rhs))) {
@@ -297,7 +297,7 @@ public final Object doLongFraction(final long lhs, final long rhs,
 
         @SuppressWarnings("unused")
         @Specialization(guards = {"isOverflowDivision(lhs, rhs)"})
-        public final LargeIntegerObject doLongOverflow(final long lhs, final long rhs) {
+        protected final LargeIntegerObject doLongOverflow(final long lhs, final long rhs) {
             return LargeIntegerObject.createLongMinOverflowResult(getContext());
         }
 
@@ -351,13 +351,13 @@ protected static final long doLongLargeInteger(final long lhs, final LargeIntege
     @SqueakPrimitive(indices = 13)
     protected abstract static class PrimQuoNode extends AbstractArithmeticPrimitiveNode implements BinaryPrimitiveFallback {
         @Specialization(guards = {"rhs != 0", "!isOverflowDivision(lhs, rhs)"})
-        public static final long doLong(final long lhs, final long rhs) {
+        protected static final long doLong(final long lhs, final long rhs) {
             return lhs / rhs;
         }
 
         @SuppressWarnings("unused")
         @Specialization(guards = {"isOverflowDivision(lhs, rhs)"})
-        public final LargeIntegerObject doLongOverflow(final long lhs, final long rhs) {
+        protected final LargeIntegerObject doLongOverflow(final long lhs, final long rhs) {
             return LargeIntegerObject.createLongMinOverflowResult(getContext());
         }
 
@@ -665,7 +665,7 @@ protected static final Object doLargeIntegerLong(final LargeIntegerObject lhs, f
         }
 
         @Specialization
-        protected Object doLargeInteger(final LargeIntegerObject lhs, final LargeIntegerObject rhs) {
+        protected static final Object doLargeInteger(final LargeIntegerObject lhs, final LargeIntegerObject rhs) {
             return lhs.floorMod(rhs);
         }
     }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/IOPrimitives.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/IOPrimitives.java
index 8d20f6b15..4072b5a9e 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/IOPrimitives.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/IOPrimitives.java
@@ -517,7 +517,7 @@ protected static final void doFail(final ArrayObject rcvr, final long start, fin
                 throw PrimitiveFailed.GENERIC_ERROR;
             }
 
-            protected final ArrayObjectSizeNode getSizeNode() {
+            private ArrayObjectSizeNode getSizeNode() {
                 if (sizeNode == null) {
                     CompilerDirectives.transferToInterpreterAndInvalidate();
                     sizeNode = insert(ArrayObjectSizeNode.create());
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/process/SignalSemaphoreNode.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/process/SignalSemaphoreNode.java
index ddfac5552..1da3f2f84 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/process/SignalSemaphoreNode.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/nodes/process/SignalSemaphoreNode.java
@@ -27,14 +27,14 @@ public static SignalSemaphoreNode create() {
     public abstract void executeSignal(VirtualFrame frame, Object semaphore);
 
     @Specialization(guards = {"isSemaphore(semaphore)", "semaphore.isEmptyList(readNode)"}, limit = "1")
-    public static final void doSignalEmpty(final PointersObject semaphore,
+    protected static final void doSignalEmpty(final PointersObject semaphore,
                     @Shared("readNode") @Cached final AbstractPointersObjectReadNode readNode,
                     @Shared("writeNode") @Cached final AbstractPointersObjectWriteNode writeNode) {
         writeNode.execute(semaphore, SEMAPHORE.EXCESS_SIGNALS, readNode.executeLong(semaphore, SEMAPHORE.EXCESS_SIGNALS) + 1);
     }
 
     @Specialization(guards = {"isSemaphore(semaphore)", "!semaphore.isEmptyList(readNode)"}, limit = "1")
-    public static final void doSignal(final VirtualFrame frame, final PointersObject semaphore,
+    protected static final void doSignal(final VirtualFrame frame, final PointersObject semaphore,
                     @Shared("readNode") @Cached final AbstractPointersObjectReadNode readNode,
                     @Shared("writeNode") @Cached final AbstractPointersObjectWriteNode writeNode,
                     @Cached final ResumeProcessNode resumeProcessNode) {
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/FrameAccess.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/FrameAccess.java
index d4f383fc8..30611ac2a 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/FrameAccess.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/FrameAccess.java
@@ -189,10 +189,6 @@ public static ContextObject getContext(final Frame frame) {
         return (ContextObject) frame.getObject(SlotIndicies.THIS_CONTEXT.ordinal());
     }
 
-    public static boolean hasContext(final VirtualFrame frame) {
-        return FrameAccess.getContext(frame) != null;
-    }
-
     public static boolean hasEscapedContext(final VirtualFrame frame) {
         final ContextObject context = getContext(frame);
         return context != null && context.hasEscaped();
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/MethodCacheEntry.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/MethodCacheEntry.java
index 379f32a90..da3565c33 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/MethodCacheEntry.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/MethodCacheEntry.java
@@ -16,9 +16,6 @@ public final class MethodCacheEntry {
     private NativeObject selector;
     private Object result;
 
-    public MethodCacheEntry() {
-    }
-
     public ClassObject getClassObject() {
         return classObject;
     }
diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/UnsafeUtils.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/UnsafeUtils.java
index a8d5f41e7..2ea49a3df 100644
--- a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/UnsafeUtils.java
+++ b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/UnsafeUtils.java
@@ -188,7 +188,7 @@ public static short getShortFromBytes(final byte[] bytes, final long index) {
         return UNSAFE.getShort(bytes, Unsafe.ARRAY_BYTE_BASE_OFFSET + index * Unsafe.ARRAY_BYTE_INDEX_SCALE);
     }
 
-    public static Unsafe initUnsafe() {
+    private static Unsafe initUnsafe() {
         try {
             // Fast path when we are trusted.
             return Unsafe.getUnsafe();