Is there any documentation for the Dia (diagram editor) module for python?

Question

The Dia diagram editor has a python module named dia that comes with the installation of the editor. It can be used to write plugins for the editor but I can't seem to find any documentation for it. I would like to know what classes/methods are defined in the module so I can write my plugin. The only example I was able to find was a hello world plugin which is particularly useless for understanding the module.

Are the any resources/code snippets that could be used to gather further understanding of this module? I would like to get information about diagram elements in a diagram, I'm trying to write a custom export function basically.