def RegisterTextKey(cls, key, atomid):
        """Register a text key.

        If the key you need to register is a simple one-to-one mapping
        of MP4 atom name to EasyMP4Tags key, then you can use this
        function::

            EasyMP4Tags.RegisterTextKey("artist", "\xa9ART")
        """
        def getter(tags, key):
            return tags[atomid]

        def setter(tags, key, value):
            tags[atomid] = value

        def deleter(tags, key):
            del(tags[atomid])

        cls.RegisterKey(key, getter, setter, deleter)