Why should we save the urimatcher definition in static flower brackets in the content provider?

I have doubts about the content provider.
Every time I write a content provider, I put the MATCHER URI definition in static brackets, but the MATCHER URI is declared a private member of the class data. Only the definition (new UriMatcher) is placed in static brackets.

Someone please tell me the reason. I tried google search but could not find the answer. I will try too, please let me know if anyone already knows.

Thanks and Regards,
SSuman185