def _CheckNoIn(input_api, output_api):
  """Checks that corpus tests don't contain .in files. Corpus tests should be
  .pdf files, having both can cause race conditions on the bots, which run the
  tests in parallel.
  """
  results = []
  for f in input_api.AffectedFiles(include_deletes=False):
    if f.LocalPath().endswith('.in'):
      results.append(output_api.PresubmitError(
          'Remove %s since corpus tests should not use .in files' % f.LocalPath()))
  return results