made typing classes inheritable; added MutableSequence and List

jedi/evaluate/jedi_typing.py

@@ -0,0 +1,25 @@
+"""
+This module is not intended to be used in jedi, rather it will be fed to the
+jedi-parser to replace classes in the typing module
+"""
+
+from collections import abc
+
+
+def factory(typing_name, indextype):
+    class Sequence(abc.Sequence):
+        def __getitem__(self) -> indextype:
+            pass
+
+    class MutableSequence(Sequence, abc.MutableSequence):
+            pass
+
+    class List(MutableSequence, list):
+            pass
+
+    dct = {
+        "Sequence": Sequence,
+        "MutableSequence": MutableSequence,
+        "List": List,
+    }
+    return dct[typing_name]