[cairo] HandlePoint: where might it be?

[Allen]

Hello all,

does anyone know where the "HandlePoint" class is in Cairo?  I'm using 
"View of /cairo-demo/cairo-in-motion/cairo-samples.c"  as an example of 
how to move an object in a drawingArea, which has a cairo context and 
this code uses the class HandlePoint but I can't find it.

The example code is located here:
http://webcvs.cairographics.org/cairo-demo/cairo-in-motion/  

and the class is used in the file cairo-samples.cpp.

Thanks ahead of time!

--Allen