docs: def unescape_code_start(source, ext, language='python'):
      """Unescape code start"""
      parser = StringParser(language)
      for pos, line in enumerate(source):
          if not parser.is_quoted() and is_escaped_code_start(line, ext):
              unescaped = unesc(line, language)
              # don't remove comment char if we break the code start...
              if is_escaped_code_start(unescaped, ext):
                  source[pos] = unescaped
          parser.read_line(line)
      return source