code: def _thread_proc(self):
      
      # Call the phase, save the return value, or default it to CONTINUE.
      phase_return = self._phase_desc(self._test_state)
      if phase_return is None:
        phase_return = openhtf.PhaseResult.CONTINUE
  
      # If phase_return is invalid, this will raise, and _phase_execution_outcome
      # will get set to the InvalidPhaseResultError in _thread_exception instead.
      self._phase_execution_outcome = PhaseExecutionOutcome(phase_return)
docs: Execute the encompassed phase and save the result.