1  import os
   2  import sys
   3  from typing import Any, BinaryIO, Callable, List, Optional, Protocol, Text, Union, overload
   4  
   5  class _ReadableBinary(Protocol):
   6      def tell(self) -> int: ...
   7      def read(self, size: int) -> bytes: ...
   8      def seek(self, offset: int) -> Any: ...
   9  
  10  if sys.version_info >= (3, 6):
  11      _File = Union[Text, os.PathLike[Text], _ReadableBinary]
  12  else:
  13      _File = Union[Text, _ReadableBinary]
  14  
  15  @overload
  16  def what(file: _File, h: None = ...) -> Optional[str]: ...
  17  @overload
  18  def what(file: Any, h: bytes) -> Optional[str]: ...
  19  
  20  tests: List[Callable[[bytes, Optional[BinaryIO]], Optional[str]]]
  21