code: def polarity_inverse(waveform, sample_rate):
      return -waveform
  
imports: import math
  import random
  from typing import Dict, List, Optional, Tuple, Union
  import numpy
  import torch
  import torchaudio
label_desc: Use image node_id 15 for calling a global function with example usage: polarity_inverse(waveform, sample_rate) and returns: unknown