This is a pathetic attempt to make samples for the library. It suffers the same problem as the library itself: no time.
It should get better soon
In order to fully understand this (and use the hundreds of things not demonstrated), you should:
a) Read the XForms docs b) Read the pyxforms/init.py file c) Read all the .c files
Anyway, it's just a sampler, this should get MUCH more complete soon