Redactor Widget With S3 Functions

I have noticed that within the default yiitext redactor widget, that they’re S3 functions but not sure how to use them as there is zero documentation on it.

I am not even sure how its appending .html to each function when clicked. Any help? Thanks.

EDIT: Realized I can’t post the code or even embed a link so this question may look a bit odd. But upon clicking the image button within Redactor it tries to load post/imageList.html