def __init__(self, identifier, source, destination, amount, start_time,
controller):
self.identifier = identifier
self.source = source
self.destination = destination
self.amount = amount
self.total = amount
self.done = False
self.start_time = start_time
self.event_scheduler = None
self.logger = None
self.ack_tracker = PacketTracker()
assert isinstance(controller, CongestionController)
self.controller = controller
