def _add_tagged_relationship(t_x, tag_search, tag_other_end):
    """
    This function all create or update the directional tagged relationship between the twitter
    account being search to the tag found in searching the twitter account.
    :param t_x: Neo4j driver transaction.
    :param tag_search: Twitter tag of who is being searched.
    :param tag_other_end: Twitter tag of who has been found.
    :return:
    """
    tag_search = tag_search.lower()
    tag_other_end = tag_other_end.lower()
    t_x.run('MATCH (n:Person) WHERE n.twitter_tag={tag_search} ' +
        'MATCH (m:Person) WHERE m.twitter_tag={tag_other_end} ' +
        'MERGE (n)-[t:Tagged]->(m) ' +
        'ON CREATE SET t.times_mentioned = 1 ' +
        'ON MATCH SET t.times_mentioned = t.times_mentioned + 1',
        tag_search=tag_search, tag_other_end=tag_other_end)
