new_contents: #!/usr/bin/env python2.7
  
  # Copyright 2015, Google Inc.
  # All rights reserved.
  #
  # Redistribution and use in source and binary forms, with or without
  # modification, are permitted provided that the following conditions are
  # met:
  #
  #     * Redistributions of source code must retain the above copyright
  # notice, this list of conditions and the following disclaimer.
  #     * Redistributions in binary form must reproduce the above
  # copyright notice, this list of conditions and the following disclaimer
  # in the documentation and/or other materials provided with the
  # distribution.
  #     * Neither the name of Google Inc. nor the names of its
  # contributors may be used to endorse or promote products derived from
  # this software without specific prior written permission.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  # check for directory level 'README.md' files
  # check that all implementation and interface files have a \file doxygen comment
  
  import os
  import sys
  
  # where do we run
  _TARGET_DIRS = [
    'include/grpc',
    'include/grpc++',
    'src/core',
    'src/cpp',
    'test/core',
    'test/cpp'
  ]
  
  # which file extensions do we care about
  _INTERESTING_EXTENSIONS = [
    '.c',
    '.h',
    '.cc'
  ]
  
  # find our home
  _ROOT = os.path.abspath(
      os.path.join(os.path.dirname(sys.argv[0]), '../../..'))
  os.chdir(_ROOT)
  
  errors = 0
  
  # walk directories, find things
  for target_dir in _TARGET_DIRS:
    for root, dirs, filenames in os.walk(target_dir):
      if 'README.md' not in filenames:
        print '%s: missing README.md' % root
        errors += 1
      for filename in filenames:
        if os.path.splitext(filename)[1] not in _INTERESTING_EXTENSIONS:
          continue
        path = os.path.join(root, filename)
        with open(path) as f:
          contents = f.read()
        if '\\file' not in contents:
          print '%s: no \\file comment' % path
          errors += 1
  
  assert errors == 0, 'error count = %d' % errors
  
subject: Add a script to list undocumented files and directories