'Load a certificate chain from a file
:param certfile: The name of the certificate chain file (``bytes`` or
``unicode``).
:return: None'

def use_certificate_chain_file(self, certfile):

    certfile = _path_string(certfile)
    result = _lib.SSL_CTX_use_certificate_chain_file(self._context, certfile)
    if (not result):
        _raise_current_error()
