ImageBBox Can't Be Used as `y`

I’m building a deep learning model for object detection using version 1.0.59. I have a get_y_func which takes in a path to an image and returns an ImageBBox containing the bounding box info for that image. When I use this in the data block api, I get an error saying TypeError: 'ImageBBox' object does not support indexing.

Can anyone point me to a reference of what kind of data is acceptable for the .label_from_func(...) method?

Figured it out – essentially it expected get_y_func to return an object of the form [ bbs, labs ], where bbs is a list of bounding boxes in “top left bottom right” format, and labs is a list of ints specifying the class of the bounding box.

E.g.:

[ [[123,111,234,222],[330,200,400,300]],[1,0]]