code: def work_experience(self, working_start_age: int = 22) -> int:
          
          age = self._store['age']
          if age == 0:
              age = self.age()
  
          return max(age - working_start_age, 0)
docs: Get a work experience.
  
          :param working_start_age: Age then person start to work.
          :return: Depend on previous generated age.