@@ -212,19 +212,19 @@ def iter_change_type(self, change_type: Lit_change_type) -> Iterator[T_Diff]:
         if change_type not in self.change_type:
             raise ValueError("Invalid change type: %s" % change_type)
 
-        for diff in self:
-            if diff.change_type == change_type:
-                yield diff
-            elif change_type == "A" and diff.new_file:
-                yield diff
-            elif change_type == "D" and diff.deleted_file:
-                yield diff
-            elif change_type == "C" and diff.copied_file:
-                yield diff
-            elif change_type == "R" and diff.renamed:
-                yield diff
-            elif change_type == "M" and diff.a_blob and diff.b_blob and diff.a_blob != diff.b_blob:
-                yield diff
+        for diffidx in self:
+            if diffidx.change_type == change_type:
+                yield diffidx
+            elif change_type == "A" and diffidx.new_file:
+                yield diffidx
+            elif change_type == "D" and diffidx.deleted_file:
+                yield diffidx
+            elif change_type == "C" and diffidx.copied_file:
+                yield diffidx
+            elif change_type == "R" and diffidx.renamed:
+                yield diffidx
+            elif change_type == "M" and diffidx.a_blob and diffidx.b_blob and diffidx.a_blob != diffidx.b_blob:
+                yield diffidx
         # END for each diff
 
 
 
@@ -41,7 +41,7 @@
 from gitdb.base import IStream
 from gitdb.db import MemoryDB
 
-import git.diff as diff
+import git.diff as git_diff
 import os.path as osp
 
 from .fun import (
@@ -88,7 +88,7 @@
 __all__ = ('IndexFile', 'CheckoutError')
 
 
-class IndexFile(LazyMixin, diff.Diffable, Serializable):
+class IndexFile(LazyMixin, git_diff.Diffable, Serializable):
 
     """
     Implements an Index that can be manipulated using a native implementation in
@@ -575,8 +575,8 @@ def write_tree(self) -> Tree:
         root_tree._cache = tree_items  # type: ignore
         return root_tree
 
-    def _process_diff_args(self, args: List[Union[str, diff.Diffable, object]]
-                           ) -> List[Union[str, diff.Diffable, object]]:
+    def _process_diff_args(self, args: List[Union[str, git_diff.Diffable, object]]
+                           ) -> List[Union[str, git_diff.Diffable, object]]:
         try:
             args.pop(args.index(self))
         except IndexError:
@@ -1272,10 +1272,11 @@ def reset(self, commit: Union[Commit, 'Reference', str] = 'HEAD', working_tree:
         return self
 
     @ default_index
-    def diff(self, other: Union[diff.Diffable.Index, 'IndexFile.Index', Treeish, None, object] = diff.Diffable.Index,
+    def diff(self,
+             other: Union[git_diff.Diffable.Index, 'IndexFile.Index', Treeish, None, object] = git_diff.Diffable.Index,
              paths: Union[str, List[PathLike], Tuple[PathLike, ...], None] = None,
              create_patch: bool = False, **kwargs: Any
-             ) -> diff.DiffIndex:
+             ) -> git_diff.DiffIndex:
         """Diff this index against the working copy or a Tree or Commit object
 
         For a documentation of the parameters and return values, see,
@@ -1287,7 +1288,7 @@ def diff(self, other: Union[diff.Diffable.Index, 'IndexFile.Index', Treeish, Non
         """
         # index against index is always empty
         if other is self.Index:
-            return diff.DiffIndex()
+            return git_diff.DiffIndex()
 
         # index against anything but None is a reverse diff with the respective
         # item. Handle existing -R flags properly. Transform strings to the object
 
@@ -5,7 +5,7 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
 from git.util import IterableList, join_path
-import git.diff as diff
+import git.diff as git_diff
 from git.util import to_bin_sha
 
 from . import util
@@ -180,7 +180,7 @@ def __delitem__(self, name: str) -> None:
     #} END mutators
 
 
-class Tree(IndexObject, diff.Diffable, util.Traversable, util.Serializable):
+class Tree(IndexObject, git_diff.Diffable, util.Traversable, util.Serializable):
 
     """Tree objects represent an ordered list of Blobs and other Trees.
 
 
@@ -469,7 +469,7 @@ def __getattr__(self, attr: str) -> Any:
     def _config_section_name(self) -> str:
         return 'remote "%s"' % self.name
 
-    def _set_cache_(self, attr: str) -> Any:
+    def _set_cache_(self, attr: str) -> None:
         if attr == "_config_reader":
             # NOTE: This is cached as __getattr__ is overridden to return remote config values implicitly, such as
             # in print(r.pushurl)