replace self param with more appropriate cls in classmethods (pythonGH-31402) (python#31445)

(cherry picked from commit a3fcca4)

Co-authored-by: Josh Smith <[email protected]>

Co-authored-by: Josh Smith <[email protected]>

Author: 2 people

Lib/_collections_abc.py

@@ -816,7 +816,7 @@ class KeysView(MappingView, Set):
     __slots__ = ()
 
     @classmethod
-    def _from_iterable(self, it):
+    def _from_iterable(cls, it):
         return set(it)
 
     def __contains__(self, key):
@@ -834,7 +834,7 @@ class ItemsView(MappingView, Set):
     __slots__ = ()
 
     @classmethod
-    def _from_iterable(self, it):
+    def _from_iterable(cls, it):
         return set(it)
 
     def __contains__(self, item):