class_docstr: This class stores the segmentation masks for all objects in one image, in
  the form of bitmaps.
  
  Attributes:
      tensor: bool Tensor of N,H,W, representing N instances in the image.
class_docstr_tok: ["This","class","stores","the","segmentation","masks","for","all","objects","in","one","image",",","in","the","form","of","bitmaps",".","Attributes",":","tensor",":","bool","Tensor","of","N",",","H",",","W",",","representing","N","instances","in","the","image","."]
code: def device(self) -> torch.device:
      return self.tensor.device
  
imports: import copy
  import itertools
  import numpy
  from typing import Any, Iterator, List, Union
  import pycocotools.mask
  import torch
  from torch import device
  from detectron2.layers.roi_align import ROIAlign
  from detectron2.utils.memory import retry_if_cuda_oom
  from .boxes import Boxes
label_desc: Use image node_id 3 for calling the BitMasks obj's underlying member method code with example usage: obj.device() and returns: self