code: def clear_bank_1(self, bits):
          
          res = yield from self._pigpio_aio_command(_PI_CMD_BC1, bits, 0)
          return _u2i(res)
docs: Clears gpios 0-31 if the corresponding bit in bits is set.
  
          bits:= a 32 bit mask with 1 set if the corresponding gpio is
               to be cleared.
  
          A returned status of PI_SOME_PERMITTED indicates that the user
          is not allowed to write to one or more of the gpios.
  
          ...
          pi.clear_bank_1(int("111110010000",2))
          ...