code: def day_of_week(self, abbr: bool = False) -> str:
          
          key = 'abbr' if abbr else 'name'
          days = self._data['day'].get(key)
          return self.random.choice(days)
docs: Get a random day of week.
  
          :param abbr: Abbreviated day name.
          :return: Day of the week.