How to use the ocpp.v16.ChargePoint function in ocpp

async def test_send_call_with_timeout(connection):
    cs = ChargePoint(
        id=1234,
        connection=connection,
        response_timeout=0.1
    )

    payload = call.ResetPayload(type="Hard")

    with pytest.raises(asyncio.TimeoutError):
        await cs.call(payload)

    # Verify that lock is released if call() crahses. Not releasing the lock
    # in case of an exception could lead to a deadlock. See
    # https://github.com/mobilityhouse/ocpp/issues/46
    assert cs._call_lock.locked() is False

import websockets
except ModuleNotFoundError:
    print("This example relies on the 'websockets' package.")
    print("Please install it by running: ")
    print()
    print(" $ pip install websockets")
    import sys
    sys.exit(1)

from ocpp.routing import on
from ocpp.v16 import ChargePoint as cp
from ocpp.v16.enums import Action, RegistrationStatus
from ocpp.v16 import call_result


class ChargePoint(cp):
    @on(Action.BootNotification)
    def on_boot_notitication(self, charge_point_vendor, charge_point_model, **kwargs):
        return call_result.BootNotificationPayload(
	    current_time=datetime.utcnow().isoformat(),
	    interval=10,
	    status=RegistrationStatus.accepted
	)


async def on_connect(websocket, path):
    """ For every new charge point that connects, create a ChargePoint instance
    and start listening for messages.

    """
    charge_point_id = path.strip('/')
    cp = ChargePoint(charge_point_id, websocket)

import websockets
except ModuleNotFoundError:
    print("This example relies on the 'websockets' package.")
    print("Please install it by running: ")
    print()
    print(" $ pip install websockets")
    import sys
    sys.exit(1)


from ocpp.v16 import call
from ocpp.v16 import ChargePoint as cp
from ocpp.v16.enums import RegistrationStatus


class ChargePoint(cp):
    async def send_boot_notification(self):
        request = call.BootNotificationPayload(
            charge_point_model="Optimus",
            charge_point_vendor="The Mobility House"
        )

        response = await self.call(request)

        if response.status ==  RegistrationStatus.accepted:
            print("Connected to central system.")


async def main():
    async with websockets.connect(
        'ws://localhost:9000/CP_1',
         subprotocols=['ocpp1.6']