code: def mix(sources_list):
      """Do the mixing"""
      # Initialize mixture
      mixture = np.zeros_like(sources_list[0])
      for source in sources_list:
          mixture += source
      return mixture
  
imports: import os
  import argparse
  import soundfile
  import pandas
  import numpy
  import functools
  from scipy.signal import resample_poly
  import tqdm.contrib.concurrent
  import glob
  import shutil
label_desc: Use image node_id 17 for calling a global function with example usage: mix(sources_list) and returns: mixture