Using transformers with fastai v2

Based in your tutorial I am trying to use It for creating a DataLoader for MaskRCNN:

class MaskRCNN(dict):
    
    @classmethod
    def create(cls, dictionary): 
        return cls(dict({x:dictionary[x] for x in dictionary.keys()}))
    
    def show(self, ctx=None, **kwargs): 
        dictionary = self
        
        boxes = dictionary["boxes"]
        labels = dictionary["labels"]
        masks = dictionary["masks"]
        
        result = masks
        return show_image(result, ctx=ctx, **kwargs)
def MaskRCNNBlock(): 
    return TransformBlock(type_tfms=MaskRCNN.create, batch_tfms=IntToFloatTensor)
def get_bbox(o):
    label_path = get_y_fn(o)
    mask=PILMask.create(label_path)
    pos = np.where(mask)
    xmin = np.min(pos[1])
    xmax = np.max(pos[1])
    ymin = np.min(pos[0])
    ymax = np.max(pos[0])
    
    return TensorBBox.create([xmin, ymin, xmax, ymax])
    
def get_bbox_label(o):
    
    return TensorCategory([1])
    
    
def get_mask(o):
    label_path = get_y_fn(o)
    mask=PILMask.create(label_path)
    mask=image2tensor(mask)
    return TensorMask(mask)

def get_dict(o):
    return {"boxes": get_bbox(o), "labels": get_bbox_label(o),"masks": get_mask(o)}
    

getters = [lambda o: o, get_dict]
maskrccnnDataBlock = DataBlock(
    blocks=(ImageBlock, MaskRCNNBlock),
    get_items=partial(get_image_files,folders=[manual_name]),
    getters=getters,
    splitter=RandomSplitter(valid_pct=0.1,seed=2020),
    item_tfms=Resize((size,size)),
    batch_tfms=Normalize.from_stats(*imagenet_stats)
)
maskrccnnDataBlock.summary(path_images)
dls = maskrccnnDataBlock.dataloaders(path_images,bs=bs)
dls.show_batch()

However, show_batch is not working owing to the fact that Mask is not getting resized to the same size as Image