code: def set_mode(self, gpio, mode):
          
          res = yield from self._pigpio_aio_command(_PI_CMD_MODES, gpio, mode)
          return _u2i(res)
docs: Sets the gpio mode.
  
          gpio:= 0-53.
          mode:= INPUT, OUTPUT, ALT0, ALT1, ALT2, ALT3, ALT4, ALT5.
  
          ...
          pi.set_mode( 4, apigpio.INPUT)  # gpio  4 as input
          pi.set_mode(17, apigpio.OUTPUT) # gpio 17 as output
          pi.set_mode(24, apigpio.ALT2)   # gpio 24 as ALT2
          ...