def AddHeadwayPeriod(self, start_time, end_time, headway_secs,
      problem_reporter=problems_module.default_problem_reporter):
    """Deprecated. Please use AddFrequency instead."""
    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)