code: def assert_event(self, txn_hash, event_name, args, timeout=5):
          
          def assert_args(event):
              assert event['args'] == args, f'{event["args"]} == {args}'
          self.add(txn_hash=txn_hash, event_name=event_name, callback=assert_args)
          self.check(timeout=timeout)
docs: Assert that `event_name` is emitted with the `args`
  
          For use in tests only.