DataBunch for MaskRCNN type dataset

Hi, I am trying to implement MaskRCNN using fastai framework. I need to create a ItemList with Item that can hold segment, bbox and key_points. How do I go about it?

So far I have thought of implementing this in lines of below snippet of code. Appreciate your comments.
Thanks in advance.


class ImageSegmentsAndKeyPoints(ImageBBox):
     bbox: FlowField
     point: FlowField
     segment: Image

    def show():
         ...
     

class MaskCategoryList(ObjectCategoryList, SegmentationCategoryList):
    ...

    def get(self, i):
        return ImageSegmentsAndKeyPoints.create(
            *_get_size(self.x, i),
            *self.items[i],
            classes=self.classes,
            pad_idx=self.pad_idx,
        )

    ...


class MaskItemList(MaskCategoryList):
    ...