@classmethod
def set_default_tokens(cls, api_token, user_token):
    """Set default pushover credentials.

        They can be set e.g. on startup of your program. If you set the default tokens here,
        you don't need to provide the tokens on every :meth:`send` call. The tokens provided as
        arguments to :meth:`send` are overriding the tokens set with this method."""
    cls._api_token = api_token
    cls._user_token = user_token
