docs: def last_room_temp(self):
          """Return avg room temperature for last session."""
          try:
              rmtemps = self.intervals[1]['timeseries']['tempRoomC']
          except KeyError:
              return None
          tmp = 0
          num_temps = len(rmtemps)
  
          if num_temps == 0:
              return None
  
          for temp in rmtemps:
              tmp += temp[1]
          rmtemp = tmp/num_temps
          return rmtemp