def set_queue_metadata(self, queue_name, metadata=None, timeout=None):
_validate_not_none('<STR_LIT>', queue_name)<EOL>request = HTTPRequest()<EOL>request.method = '<STR_LIT>'<EOL>request.host = self._get_host()<EOL>request.path = _get_path(queue_name)<EOL>request.query = [<EOL>('<STR_LIT>', '<STR_LIT>'),<EOL>('<STR_LIT>', _int_to_str(timeout)),<EOL>]<EOL>request.headers = [('<STR_LIT>', metadata)]<EOL>self._perform_request(request)<EOL>
Sets user-defined metadata on the specified queue. Metadata is
associated with the queue as name-value pairs.

:param str queue_name:
    The name of an existing queue.
:param dict metadata:
    A dict containing name-value pairs to associate with the
    queue as metadata.
:param int timeout:
    The server timeout, expressed in seconds.