docs: def _get_date_type(date):
          """
          Returns the type of a date.
  
          :param str|datetime.date date: The date.
  
          :rtype: str
          """
          if isinstance(date, str):
              return 'str'
  
          if isinstance(date, datetime.date):
              return 'date'
  
          if isinstance(date, int):
              return 'int'
  
          raise ValueError('Unexpected type {0!s}'.format(date.__class__))