Recommended way to extend BIDSFile classes?

I have a subclasse I would like to create for pybids for a project of mine. This would be an extension of BIDSImageFile for dwi-files, containing methods for querying bvals, bvecs, and shells as properties.

What would be the recommended way for integrating this code into pybids? My naive thought would be to conditionally assign via obj.__class__, however I was wondering if there was a more formal method for incorporating extensions like these to pybids?