Refactor

src/JSInterop/Microsoft.JSInterop/src/Infrastructure/ByteArrayJsonConverter.cs

@@ -55,11 +55,5 @@ public override void Write(Utf8JsonWriter writer, byte[] value, JsonSerializerOp
             writer.WriteNumber(ByteArrayRefKey, id);
             writer.WriteEndObject();
         }
-
-        private struct ByteArrayRef
-        {
-            [JsonPropertyName("__byte[]")]
-            public int? Id { get; set; }
-        }
     }
 }

src/JSInterop/Microsoft.JSInterop/src/Infrastructure/ByteArrayRef.cs

@@ -0,0 +1,15 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace Microsoft.JSInterop.Infrastructure
+{
+    internal struct ByteArrayRef
+    {
+        [JsonPropertyName("__byte[]")]
+        public int? Id { get; set; }
+    }
+}