docs: def get_diff(original, fixed, file_name,
               original_label='original', fixed_label='fixed'):
      """Return text of unified diff between original and fixed."""
      original, fixed = original.splitlines(True), fixed.splitlines(True)
      newline = '\n'
  
      from difflib import unified_diff
      diff = unified_diff(original, fixed,
                          os.path.join(original_label, file_name),
                          os.path.join(fixed_label, file_name),
                          lineterm=newline)
      text = ''
      for line in diff:
          text += line
          # Work around missing newline (http://bugs.python.org/issue2142).
          if not line.endswith(newline):
              text += newline + r'\ No newline at end of file' + newline
      return text