Re-added dropped header

CHANGELOG.md

@@ -6,6 +6,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
 - Add support for building for CPython limited API. This required a few minor changes to runtime behaviour of of pyo3 `#[pyclass]` types. See the migration guide for full details. [#1152](https://github.com/PyO3/pyo3/pull/1152)
 - Add argument names to `TypeError` messages generated by pymethod wrappers. [#1212](https://github.com/PyO3/pyo3/pull/1212)
 

src/types/iterator.rs

@@ -2,9 +2,9 @@
 //
 // based on Daniel Grunwald's https://github.com/dgrunwald/rust-cpython
 
-use crate::{
-    ffi, AsPyPointer, PyAny, PyDowncastError, PyErr, PyNativeType, PyResult, PyTryFrom, Python,
-};
+use crate::{ffi, AsPyPointer, PyAny, PyErr, PyNativeType, PyResult, Python};
+#[cfg(any(not(Py_LIMITED_API), Py_3_8))]
+use crate::{PyDowncastError, PyTryFrom};
 
 /// A Python iterator object.
 ///
@@ -28,6 +28,7 @@ use crate::{
 #[repr(transparent)]
 pub struct PyIterator(PyAny);
 pyobject_native_type_named!(PyIterator);
+#[cfg(any(not(Py_LIMITED_API), Py_3_8))]
 pyobject_native_type_extract!(PyIterator);
 
 impl PyIterator {
@@ -202,6 +203,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(any(not(Py_LIMITED_API), Py_3_8))]
     fn iterator_try_from() {
         let gil_guard = Python::acquire_gil();
         let py = gil_guard.python();