code: def _create_set_property_msg(self, prop, cmd, val):
          
          user_data = Userdata({'d1': self.group,
                                'd2': cmd,
                                'd3': val})
          msg = ExtendedSend(self._address,
                             COMMAND_EXTENDED_GET_SET_0X2E_0X00,
                             user_data)
          msg.set_checksum()
          self._set_sent_property(prop, val)
          return msg
docs: Create an extended message to set a property.
  
          Create an extended message with:
              cmd1: 0x2e
              cmd2: 0x00
              flags: Direct Extended
              d1: group
              d2: cmd
              d3: val
              d4 - d14: 0x00
  
          Parameters:
              prop: Property name to update
              cmd: Command value
                  0x02: on mask
                  0x03: off mask
                  0x04: x10 house code
                  0x05: ramp rate
                  0x06: on level
                  0x07: LED brightness
                  0x08: Non-Toggle mask
                  0x09: LED bit mask (Do not use in this class. Use LED class)
                  0x0a: X10 All bit mask
                  0x0c: Trigger group bit mask
              val: New property value