>I think the functions like `createSheared` and such should be defined in `ChromaticObject`. 

These all exist and are documented now.  Weirdly `GSObject.createExpanded()` was missing from base.py, so I added that too.

The return type for these is `ChromaticAffineTransform()`.  I haven't tried yet, but I think it might be possible move the `ChromaticAffineTransform` methods to `ChromaticObject` and have that be the return type, similar to what's in base.py.