docs: def file_comparison(files0, files1):
      """Compares two dictionaries of files returning their difference.
  
          {'created_files': [<files in files1 and not in files0>],
           'deleted_files': [<files in files0 and not in files1>],
           'modified_files': [<files in both files0 and files1 but different>]}
  
      """
      comparison = {'created_files': [],
                    'deleted_files': [],
                    'modified_files': []}
  
      for path, sha1 in files1.items():
          if path in files0:
              if sha1 != files0[path]:
                  comparison['modified_files'].append(
                      {'path': path,
                       'original_sha1': files0[path],
                       'sha1': sha1})
          else:
              comparison['created_files'].append({'path': path,
                                                  'sha1': sha1})
      for path, sha1 in files0.items():
          if path not in files1:
              comparison['deleted_files'].append({'path': path,
                                                  'original_sha1': files0[path]})
  
      return comparison