code: def _add_key(example):
      """Add a key to this example by taking the hash of the values."""
      return hash(example["audio"].tobytes()), example
  
file_path: ddsp/ddsp/training/data_preparation/prepare_tfrecord_lib.py
imports: from absl import logging
  import apache_beam
  from ddsp import spectral_ops
  import numpy
  import pydub
  import tensorflow.compat.v2
label_desc: Use image node_id 8 for calling a global function with example usage: _add_key(example) and returns: hash,  example