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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 new_workunit(self, name, labels=None, cmd='', log_config=None):
 """Create a new workunit under the calling thread's current workunit. :API: public """

    with self.run_tracker.new_workunit(name=name, labels=labels, cmd=cmd, log_config=log_config) as workunit:
      yield workunit