def _missing_datetimes(self, finite_datetimes):
        """
        Backward compatible wrapper. Will be deleted eventually (stated on Dec 2015)
        """
        try:
            return self.missing_datetimes(finite_datetimes)
        except TypeError as ex:
            if 'missing_datetimes()' in repr(ex):
                warnings.warn('In your Range* subclass, missing_datetimes() should only take 1 argument (see latest docs)')
                return self.missing_datetimes(self.of_cls, finite_datetimes)
            else:
                raise