@classmethod
def from_trackable(cls, trackable):
    """Return :class:`.Cache` instance from :class:`.Trackable`.

        This only makes sense, if trackable is currently placed in cache. Otherwise it will have
        unexpected behavior.

        :param .Trackable trackable: Source trackable.
        """
    return cls(trackable.geocaching, None, url=trackable.location_url)
