def METHOD_NAME(self, tag=None):
    """Add a tag to the object.
    Args:
        tag (obj): Key value pair to set tag.
    Returns:
        list({str:str}): a list of key value pairs
    """
    logger.warning(
        "set_tag on Association is deprecated. Use set_tag on the source or destination\
         entity instead."
    )
    return self._set_tags(resource_arn=self.source_arn, tags=[tag])