# Buggy code
async def _cleanup(self) -> None:
    for rule_name, rule_id in self._rules.items():
        logger.debug("Removing rule {0}, ID: {1}".format(rule_name, rule_id))
        await self._bus.delMatch(rule_id).asFuture(self.loop)

    await asyncio.gather(*(self.stop_notify(_uuid) for _uuid in self._subscriptions))


# Traceback (bleak.exc.BleakError)
/Users/zaytsev/PycharmProjects/bluetooth/venv/bin/python /Users/zaytsev/PycharmProjects/bluetooth/bleak_demo.py
DEBUG:bleak.backends.corebluetooth.CentralManagerDelegate:Bluetooth powered on
DEBUG:bleak.backends.corebluetooth.CentralManagerDelegate:Discovered device A0E49DB2-B7F1-4A65-AB2E-D75121192329: Unknown @ RSSI: -79
A0E49DB2-B7F1-4A65-AB2E-D75121192329: HUAWEI Band 2-b6e
DEBUG:bleak.backends.corebluetooth.client:Connecting to BLE device @ A0E49DB2-B7F1-4A65-AB2E-D75121192329
DEBUG:bleak.backends.corebluetooth.CentralManagerDelegate:Successfully connected to device uuid A0E49DB2-B7F1-4A65-AB2E-D75121192329
WARNING:bleak.backends.corebluetooth.PeripheralDelegate:PeripheralDelegate is not compliant
DEBUG:bleak.backends.corebluetooth.client:Retrieving services...
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Services discovered
DEBUG:bleak.backends.corebluetooth.client:Retrieving characteristics for service 180F
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Characteristics discovered
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A19
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A19
DEBUG:bleak.backends.corebluetooth.client:Retrieving characteristics for service 180A
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Characteristics discovered
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A29
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A29
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A24
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A24
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A26
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A26
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A28
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A28
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A50
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A50
DEBUG:bleak.backends.corebluetooth.client:Retrieving characteristics for service 180D
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Characteristics discovered
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A37
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A37
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic 2A38
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered 2A38
DEBUG:bleak.backends.corebluetooth.client:Retrieving characteristics for service FE86
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Characteristics discovered
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic FE01
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered FE01
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic FE02
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered FE02
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic FE03
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered FE03
DEBUG:bleak.backends.corebluetooth.client:Retrieving descriptors for characteristic FE04
DEBUG:bleak.backends.corebluetooth.PeripheralDelegate:Descriptor discovered FE04
DEBUG:bleak.backends.corebluetooth.client:Retrieving services...
DEBUG:bleak.backends.corebluetooth.client:Retrieving characteristics for service 180F
DEBUG:bleak.backends.corebluetooth.CentralManagerDelegate:Peripheral Device disconnected!
Traceback (most recent call last):
File "/Users/zaytsev/PycharmProjects/bluetooth/bleak_demo.py", line 25, in <module>
loop.run_until_complete(ble_get_services(address, loop))
File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/base_events.py", line 579, in run_until_complete
return future.result()
File "/Users/zaytsev/PycharmProjects/bluetooth/bleak_demo.py", line 18, in ble_get_services
svcs = await client.get_services()
File "/Users/zaytsev/PycharmProjects/bluetooth/venv/lib/python3.7/site-packages/bleak/backends/corebluetooth/client.py", line 118, in get_services
self.services.add_service(BleakGATTServiceCoreBluetooth(service))
File "/Users/zaytsev/PycharmProjects/bluetooth/venv/lib/python3.7/site-packages/bleak/backends/service.py", line 101, in add_service
"This service is already present in this BleakGATTServiceCollection!"
bleak.exc.BleakError: This service is already present in this BleakGATTServiceCollection!

# Fixed code
async def _cleanup(self) -> None:
    for rule_name, rule_id in self._rules.items():
        logger.debug("Removing rule {0}, ID: {1}".format(rule_name, rule_id))
        try:
            await self._bus.delMatch(rule_id).asFuture(self.loop)
        except Exception as e:
            logger.error(
                "Could not remove rule {0} ({1}): {2}".format(rule_id, rule_name, e)
            )
    self._rules = {}
    await asyncio.gather(*(self.stop_notify(_uuid) for _uuid in self._subscriptions))