new_contents: import time
  
  from mock import mock_open, patch
  
  from publish2cloud import chunk_metadata
  
  
  def test_chunk_metadata():
      """Test getting metadata from the chunk header of a list file."""
      chunknum = int(time.time())
      # Hash of test-track-digest256.dummytracker.org/
      domain_hash = (b"q\xd8Q\xbe\x8b#\xad\xd9\xde\xdf\xa7B\x12\xf0D\xa2"
                     "\xf2\x1d\xcfx\xeaHi\x7f8%\xb5\x99\x83\xc1\x111")
      data = b"a:%d:32:32\n" % chunknum + domain_hash
  
      with patch("test_publish2cloud.open", mock_open(read_data=data)):
          with open("base-fingerprinting-track-digest256", "rb") as fp:
              metadata = chunk_metadata(fp)
  
      assert metadata["type"] == "a"
      assert metadata["num"] == str(chunknum)
      assert metadata["hash_size"] == "32"
      assert metadata["len"] == "32"
      assert metadata["checksum"] == ("043493ecb63c5f143a372a5118d04a44df"
                                      "188f238d2b18e6cd848ae413a01090")
  
subject: Add unit test for chunk_metadata