class_docstr: Model that returns pre-calculated predictions for the mask detection dataset.
code: def _hash_image(img):
      return hashlib.sha1(img).hexdigest()
  
imports: import contextlib
  import hashlib
  import json
  import os
  import pathlib
  import typing
  import urllib.request
  from pathlib import Path
  import numpy
  import torch
  from bs4 import BeautifulSoup
  from PIL import Image
  from torch import nn
  from torch.utils.data import DataLoader
  from typing_extensions import Literal
  from deepchecks.vision.utils.test_utils import IndicesSequentialSampler
  from deepchecks.vision.vision_data import BatchOutputFormat, VisionData
  from deepchecks.vision.vision_data.utils import object_to_numpy
label_desc: Use image node_id 3 for calling the MaskPrecalculatedModel obj's underlying member method code with example usage: obj._hash_image(img) and returns: hashlib