code: def _read_from_buffer(self, pos: int) -> None:
          
          self._read_bytes = self._read_delimiter = self._read_regex = None
          self._read_partial = False
          self._finish_read(pos, False)
docs: Attempts to complete the currently-pending read from the buffer.
  
          The argument is either a position in the read buffer or None,
          as returned by _find_read_pos.