def replicaset_find(client):
    """Check if a replicaset exists.

    Args:
        client (cursor): Mongodb cursor on admin database.
        replica_set (str): replica_set to check.

    Returns:
        dict: when user exists, False otherwise.
    """
    for rs in client['local'].system.replset.find({}):
        return rs['_id']
    return False
