code: def _missing_datetimes(self, finite_datetimes):
          
          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
docs: Backward compatible wrapper. Will be deleted eventually (stated on Dec 2015)