Add a comment why priority is necessary

scapy/contrib/cansocket_python_can.py

@@ -30,6 +30,12 @@
 
 
 class PriotizedCanMessage(object):
+    """Helper object for comparison of CAN messages. If the timestamps of two
+    messages are equal, the counter value of a priority counter, is used
+    for comparison. It's only important that this priority counter always
+    get increased for every CAN message in the receive heapq. This compensates
+    a low resolution of `time.time()` on some operating systems.
+    """
     def __init__(self, msg, count):
         # type: (can_Message, int) -> None
         self.msg = msg