def __init__(self, type, source, target, arguments=None, tags=None):
        """
        Initialize an Event.

        Arguments:

            type -- A string describing the event.

            source -- The originator of the event (a nick mask or a server).

            target -- The target of the event (a nick or a channel).

            arguments -- Any event-specific arguments.
        """
        self.type = type
        self.source = source
        self.target = target
        if arguments is None:
            arguments = []
        self.arguments = arguments
        if tags is None:
            tags = []
        self.tags = tags