setting and clearing RTS seems not to work

[NiklausS]

Hi,
I'm just about using your library. And it works fine so far, thank you.
However, i do not succeed in setting / clearing the RTS.
I need this to reset a esp8266 board.

the original esptool.py works like this:

    def hard_reset(self):
        self._setRTS(True)  # EN->LOW
        time.sleep(0.1)
        self._setRTS(False)

but when i do this with your lib, this seems not to do anything :-(
any idea?
python 3.8
aioserial 1.2.3
pyserial 3.4

aio1= aioserial.AioSerial(port='/dev/ttyUSB0', baudrate='115200' )
print("reset rts ")
aio1.rts=False
await asyncio.sleep(0.1)
aio1.rts=True

aio1.is_open -> this one seems to be correct and usable