@classmethod
def get_cachevault(cls, session, server_key, controller):
    """Cachevault details
        Args:
            session:  database session
            server_key(int): key of the server cachevault belongs to
            controller(int): controller num
        Returns:
            dict: information about cachevault
        """
    query = []
    query.extend([
        'MATCH (:Asset {{ key: {} }})-[:HAS_CONTROLLER]->(ctrl:Controller {{ controllerNum: {} }})'
        .format(server_key, controller),
        'MATCH (ctr)-[:HAS_CACHEVAULT]->(cv:CacheVault)', 'RETURN cv'])
    results = session.run('\n'.join(query))
    record = results.single()
    return dict(record.get('cv')) if record else None
