What does the order varible do in DisplayTransform?

I am trying to write my own custom transform that will be applied after batch. I’m trying to read some other DisplayTransform’s that have been used for after_batch such as Normalize and IntToFloatTensor. I noticed that they both have an order variable declared at the top. What does that mean? How does it get used?

class IntToFloatTensor(DisplayedTransform):

    "Transform image to float tensor, optionally dividing by 255 (e.g. for images)."

    order = 10 #Need to run after PIL transforms on the GPU

    def __init__(self, div=255., div_mask=1): store_attr()

    def encodes(self, o:TensorImage): return o.float().div_(self.div)

    def encodes(self, o:TensorMask ): return o.long() // self.div_mask

    def decodes(self, o:TensorImage): return ((o.clamp(0., 1.) * self.div).long()) if self.div else o