Compare Calendar objects

[abe-101]

What would be the correct way to compare calendar objects?

I'm working on a webapp that merges external (link) calendars
There is a routine task that pulls events from external sources, creates a single calendar object and writes it to a file.
I would only like to write to the file if there are new events
So my question is, after creating a new calendar object from the external sources how can I compare it to the calendar object written to the file?

[abe-101]

Here is the file
https://github.com/abe-101/calmerge/blob/3a4fc707649e7af8201c5405d70b59892af28d95/calmerge/calendars/utils.py

[niccokunzmann]

I would compare UUID and Recurrence-id. They would identify an event.