code: def read_noise_manifest(add_bg: bool, background_manifest: str):
      """
      Read the noise manifest file and sample the noise manifest.
  
      Args:
          add_bg (bool): Whether to add background noise.
          background_manifest (str): Path to the background noise manifest file.
  
      Returns:
          noise_manifest (list): List of the entire noise source samples.
      """
      noise_manifest = []
      if add_bg is True:
          if background_manifest is not None:
              background_manifest_list = background_manifest
              if isinstance(background_manifest_list, str):
                  background_manifest_list = [background_manifest_list]
              for background_manifest in background_manifest_list:
                  if os.path.exists(background_manifest):
                      noise_manifest += read_manifest(
                          background_manifest
                      )
                  else:
                      raise FileNotFoundError(
                          f"Noise manifest file: {background_manifest} file not found."
                      )
          else:
              raise FileNotFoundError(
                  f"Noise manifest file is {background_manifest}. Please provide a valid noise manifest file/list if add_bg=True."
              )
      return noise_manifest
  
imports: import copy
  import os
  import shutil
  from collections import defaultdict
  from typing import IO, Dict, List, Optional, Tuple
  import numpy
  import torch
  from scipy.stats import beta, gamma
  from tqdm import tqdm
  from nemo.collections.asr.parts.preprocessing.perturb import AudioAugmentor
  from nemo.collections.asr.parts.preprocessing.segment import AudioSegment
  from nemo.collections.asr.parts.utils.manifest_utils import get_ctm_line, read_manifest, write_ctm, write_manifest, write_text
  from nemo.collections.asr.parts.utils.speaker_utils import labels_to_rttmfile
  from nemo.utils import logging
label_desc: Use image node_id 14 for calling a global function with example usage: read_noise_manifest(add_bg, background_manifest) and returns: noise_manifest