def bio_shutdown(self):
        """
        If the Connection was created with a memory BIO, this method can be
        used to indicate that *end of file* has been reached on the read end of
        that memory BIO.

        :return: None
        """
        if self._from_ssl is None:
            raise TypeError("Connection sock was not None")

        _lib.BIO_set_mem_eof_return(self._into_ssl, 0)

        If the Connection was created with a memory BIO, this method can be
        used to indicate that *end of file* has been reached on the read end of
        that memory BIO.

        :return: None
        
stackoverflow/venv/lib/python3.6/site-packages/OpenSSL/SSL.py