docs: def prefix_lines(lines, prefix):
      """Add the prefix to each of the lines.
  
      >>> prefix_lines(['foo', 'bar'], '  ')
      ['  foo', '  bar']
      >>> prefix_lines('foo\\nbar', '  ')
      ['  foo', '  bar']
  
      :param list or str lines: A string or a list of strings. If a string is
          passed, the string is split using splitlines().
      :param str prefix: Prefix to add to the lines. Usually an indent.
      :returns: list
      """
      if isinstance(lines, bytes):
          lines = lines.decode('utf-8')
      if isinstance(lines, str):
          lines = lines.splitlines()
      return [prefix + line for line in lines]