old_contents: """Do an integration test. Only use simple html files."""
  
  import subprocess
  
  
  def test_valid():
      subprocess.check_call(['html5validator', '--root=tests/valid/'])
  
  
  def test_invalid():
      try:
          subprocess.check_call(['html5validator', '--root=tests/invalid/'])
      except subprocess.CalledProcessError, e:
          assert e.returncode == 1
  
new_contents: """Do an integration test. Only use simple html files."""
  
  import subprocess
  
  
  def test_valid():
      assert subprocess.call(['html5validator', '--root=tests/valid/']) == 0
  
  
  def test_invalid():
      assert subprocess.call(['html5validator', '--root=tests/invalid/']) == 1
  
subject: simplify test