new_contents: import subprocess
  import sys
  import unittest
  
  
  class StyleTest(unittest.TestCase):
      "run flake8 with the right arguments and ensure all files pass"
      def test_style(self):
          try:
              execlude = [
                  'ply',
                  'networkx',
                  'pyparsing.py',
                  'parsetab.py',
                  'test_myria_up.py'
              ]
              subprocess.check_output(
                  ['flake8',
                   '--exclude='+','.join(execlude),
                   'appengine'],
                  stderr=subprocess.STDOUT)
          except subprocess.CalledProcessError as e:
              print >> sys.stderr, e.output
              raise
  
  if __name__ == '__main__':
      unittest.main()
  
subject: add style check test.