def get_signing_key(self, key_type):
        """GetSigningKey.
        [Preview API]
        :param str key_type:
        :rtype: str
        """
        route_values = {}
        if key_type is not None:
            route_values['keyType'] = self._serialize.url('key_type', key_type, 'str')
        response = self._send(http_method='GET',
                              location_id='92ed5cf4-c38b-465a-9059-2f2fb7c624b5',
                              version='5.0-preview.1',
                              route_values=route_values)
        return self._deserialize('str', response)
GetSigningKey.
        [Preview API]
        :param str key_type:
        :rtype: str