code: def _Backward2_T_Ps(P, s):
      
      if P <= 4:
          T = _Backward2a_T_Ps(P, s)
      elif s >= 5.85:
          T = _Backward2b_T_Ps(P, s)
      else:
          T = _Backward2c_T_Ps(P, s)
  
      if P <= 22.064:
          Tsat = _TSat_P(P)
          T = max(Tsat, T)
      return T
docs: Backward equation for region 2, T=f(P,s)
  
      Parameters
      ----------
      P : float
          Pressure, [MPa]
      s : float
          Specific entropy, [kJ/kgK]
  
      Returns
      -------
      T : float
          Temperature, [K]