Having discovered that some things don't work as I'd like them to, I think in large part because I've got a dynamic IP and most developers don't, I find the need to substitute my own functions for some standard ones and ones in a plug-in.  How does one go about doing that using the My Plugin section instead of editing the php code that's in the distro?

I've determined they work by editing the existing code, but I want to do it "right".

I think I've figured out how to use event triggers to add functionality, but how does one change it?  That is, if Piwigo or a plug-in has a function do_nothing() and I want to substitute my own do_nothing() or replace it with do_something(), how do I do that (in 2.7.x) in an officially supported way?

If there is an existing plugin that will serve as an example, that would be great.