enum: add sunder methods that were new in 3.6

Author: JelleZijlstra

stdlib/3.4/enum.pyi

@@ -1,10 +1,11 @@
 # FIXME: Stub incomplete, ommissions include:
 # * the metaclass
-# * _sunder_ methods with their transformations
 
 import sys
 from typing import List, Any, TypeVar, Union
 
+_T = TypeVar('_T')
+
 class Enum:
     def __new__(cls, value: Any) -> None: ...
     def __repr__(self) -> str: ...
@@ -14,14 +15,21 @@ class Enum:
     def __hash__(self) -> Any: ...
     def __reduce_ex__(self, proto: Any) -> Any: ...
 
+    if sys.version_info >= (3, 6):
+        # mypy complains here that the type of the first argument is not 'self', but that is correct
+        # because this is an implicit staticmethod. Making it an explicit staticmethod silences
+        # mypy, but does not actually work at runtime.
+        def _generate_next_value_(name: str, start: int, count: int, last_values: List[Any]) -> Any: ...  # type: ignore
+        @classmethod
+        def _missing_(self, value: Any) -> Any: ...
+        _order_ = ...  # type: Union[str, List[str]]
+
     name = ...  # type: str
     value = ...  # type: Any
 
 class IntEnum(int, Enum):
     value = ...  # type: int
 
-_T = TypeVar('_T')
-
 def unique(enumeration: _T) -> _T: ...
 
 if sys.version_info >= (3, 6):