new_contents: #!/usr/bin/env python
  
  import subprocess
  import unittest
  
  
  class TestPy2Py3Compat(unittest.TestCase):
      """We need to be compatible with both python2 and 3.
  
      Test that we can at least import runlint.py under both.
      """
      def test_python2_compat(self):
          subprocess.check_call(['python2', '-c',  'import runlint'])
  
      def test_python3_compat(self):
          subprocess.check_call(['python3', '-c',  'import runlint'])
  
subject: Add a test that imports runlint under both python2 and python3