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
Create a new workunit under the calling thread's current workunit.

    :API: public