def get_if_all_equal(data, default=None):
    """Get value of all are the same, else return default value.
    
    Arguments:
        data {TupleTree} -- TupleTree data.
    
    Keyword Arguments:
        default {any} -- Return if all are not equal (default: {None})
    """
    if data.all_equal():
        return data[0]
    return default