code: def enable_chunked_encoding(self, chunk_size: Optional[int]=None) -> None:
          
          self._chunked = True
  
          if hdrs.CONTENT_LENGTH in self._headers:
              raise RuntimeError("You can't enable chunked encoding when "
                                 "a content length is set")
          if chunk_size is not None:
              warnings.warn('Chunk size is deprecated #1615', DeprecationWarning)
docs: Enables automatic chunked transfer encoding.