code: def read_image_bytes(filename):
      with open(
          filename,
          "rb",
      ) as fin:
          image_bytes = fin.read()
      return image_bytes
  
imports: import json
  import math
  import random
  import sys
  from pathlib import Path
  import pytest
  from torchvision.models.resnet import ResNet18_Weights
  from ts.handler_utils.micro_batching import MicroBatching
  from ts.torch_handler.image_classifier import ImageClassifier
  from ts.torch_handler.unit_tests.test_utils.mock_context import MockContext
  from ts.torch_handler.unit_tests.test_utils.model_dir import copy_files, download_model
label_desc: Use image node_id 1 for calling a global function with example usage: read_image_bytes(filename) and returns: image_bytes