code: @Override
      public int findIn(Source source) {
          Matcher matcher = REGEX_AUTHORITY.matcher(source.subToEnd());
          int offset = -1;
          while (matcher.find()) {
              int matcherPosition = source.getOffset() + matcher.start();
              if (parseLength(source, matcherPosition, null) > 0) {
                  offset = matcherPosition;
                  break;
              }
          }
          return offset;
      }
docs: {@inheritDoc}