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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def AddStopTime(self, stop, problems=None, schedule=None, **kwargs):
 """Add a stop to this trip. Stops must be added in the order visited. Args: stop: A Stop object kwargs: remaining keyword args passed to StopTime.__init__ Returns: None """

    if problems is None:
      # TODO: delete this branch when StopTime.__init__ doesn't need a
      # ProblemReporter
      problems = problems_module.default_problem_reporter
    stoptime = self.GetGtfsFactory().StopTime(
        problems=problems, stop=stop, **kwargs)
    self.AddStopTimeObject(stoptime, schedule)