MessagingUnit, receive() error

[Jun0929]

Hi,
I tried to run the codes, but I bumped into 2 problems.

First, an error occured saying that QBIMIntersectionManager requires MessagingUnit as an argument.
I fixed this by just importing MessagingUnit and put MessagingUnit in QBIMIntersectionManager
like -
"from intersection_control.core import IntersectionManager, MessagingUnit",
"intersection_managers = {QBIMIntersectionManager(intersection_id, env, 10, 0.05, MessagingUnit) for intersection_id in env.intersections.get_ids()}"

Second, in the loop -
for vehicle in vehicles:
vehicle.step()
and
for intersection_manager in intersection_managers:
intersection_manager.step()
and the error says "receive() missing 1 required positional argument: 'self'".

I tried to fix this error, but I couldn't.
Can you help me to solve it?