code: def test_is_gzip_file():
      with TemporaryDirectory() as temp:
          fname = os.path.join(temp, "test")
          assert utils.is_gzip_file(
              _touch_file(fname, compressed=True, empty=True)
          )
          assert utils.is_gzip_file(
              _touch_file(fname, compressed=True, empty=False)
          )
          assert not utils.is_gzip_file(
              _touch_file(fname, compressed=False, empty=True)
          )
          assert not utils.is_gzip_file(
              _touch_file(fname, compressed=False, empty=False)
          )
  
imports: import gzip
  import math
  import os
  import re
  from tempfile import TemporaryDirectory
  import unittest
  import numpy
  import pytest
  import torch
  from sockeye import __version__
  from sockeye import constants
  from sockeye import utils
label_desc: Use image node_id 17 for calling a global function with example usage: test_is_gzip_file() without return types