finish assignment

assignment/environment.py

@@ -80,6 +80,8 @@ class Sink(AtomicDEVS):
     def __init__(self):
         super().__init__("Sink")
         self.state = SinkState()
+
+        # On this input port, the Sink expects to receive a *list* of Ships. This is because a Lock can contain more than one Ship, and the Lock can send them all at once to the Sink (with a single event).
         self.in_ships = self.addInPort("in_ships")
 
     def extTransition(self, inputs):