code: public static HttpResponseStatus parseLine(CharSequence line) {
          return (line instanceof AsciiString) ? parseLine((AsciiString) line) : parseLine(line.toString());
      }
docs: Parses the specified HTTP status line into a {@link HttpResponseStatus}. The expected formats of the line are:
  <ul>
  <li>{@code statusCode} (e.g. 200)</li>
  <li>{@code statusCode} {@code reasonPhrase} (e.g. 404 Not Found)</li>
  </ul>
  
  @throws IllegalArgumentException if the specified status line is malformed