code: def AddHeadwayPeriod(self, start_time, end_time, headway_secs,
        problem_reporter=problems_module.default_problem_reporter):
      
      warnings.warn("No longer supported. The HeadwayPeriod class was renamed to "
                    "Frequency, and all related functions were renamed "
                    "accordingly.", DeprecationWarning)
      self.AddFrequency(start_time, end_time, headway_secs, problem_reporter)
docs: Deprecated. Please use AddFrequency instead.