def determine_triggers(triggers, add_triggers, use_triggers):
    """Determine set of effective triggers.

    :param triggers: list of configured triggers.
    :type triggers: List[str]
    :param add_triggers: additional triggers.
    :type add_triggers: List[str]
    :param use_triggers: triggers shall be applied.
    :type use_triggers: bool
    :return: list of effective triggers.
    :rtype: List[str]
    """
    if use_triggers:
        triggers_ = triggers
        triggers_.extend(add_triggers)
    else:
        triggers_ = []
    return triggers_