old_contents: import pytest
  import ots
  
  
  def test_sanitize():
      p = ots.sanitize()
      assert p.returncode == 1
      assert len(p.args) == 1
      assert p.args[0].endswith("ots-sanitize")
      assert p.stdout == None
      assert p.stderr == None
  
new_contents: from __future__ import absolute_import, unicode_literals
  import pytest
  import subprocess
  import ots
  
  
  def test_sanitize():
      p = ots.sanitize()
      assert p.returncode == 1
      assert len(p.args) == 1
      assert p.args[0].endswith("ots-sanitize")
      assert p.stdout == None
      assert p.stderr == None
  
  
  def test_check_error():
      with pytest.raises(subprocess.CalledProcessError):
          ots.sanitize("--foo", "bar", check=True)
  
  
  def test_capture_output():
      p = ots.sanitize(capture_output=True)
      assert len(p.stdout) == 0
      stderr = p.stderr.decode()
      assert stderr.startswith("Usage: ")
  
subject: add more tests