use CPN Tools V4.0.1 ONLY.
Scenario: In the Lecture we simulated the simple example of a Process
reading a file and then writing back to it. Now, imagine the scenario, with
two Process trying to read or write to the same file.
Task(s):
1. Try to implement any form of locking mechanism of your choice, so
that the file is not written to while another Process is writing to it, and
vice versa