code: def clear(self):
          
  
          self._compound_mfrs = self._compound_mfrs * 0.0
          self._P = 1.0
          self._T = 25.0
          self._H = 0.0
docs: Set all the compound mass flow rates in the stream to zero.
          Set the pressure to 1, the temperature to 25 and the enthalpy to zero.