code: def compression_type_of_files(files):
      """Return GZIP or None for the compression type of the files."""
      return "GZIP" if all(f.endswith(".gz") for f in files) else None
  
imports: import json
  from typing import Optional
  from absl import logging
  import numpy
  import tensorflow
  from deepvariant.protos import deepvariant_pb2
  from third_party.nucleus.io import sharded_file_utils
  from third_party.nucleus.io import tfrecord
  from third_party.nucleus.protos import variants_pb2
  from tensorflow.core.example import example_pb2
label_desc: Use image node_id 22 for calling a global function with example usage: compression_type_of_files(files) and returns: unknown