code: private int getIndex(byte[] name) {
      if (length() == 0 || name == null) {
        return -1;
      }
      int h = hash(name);
      int i = index(h);
      int index = -1;
      for (HeaderEntry e = headerFields[i]; e != null; e = e.next) {
        if (e.hash == h && HpackUtil.equals(name, e.name)) {
          index = e.index;
          break;
        }
      }
      return getIndex(index);
    }
docs: Returns the lowest index value for the header field name in the dynamic table.
  Returns -1 if the header field name is not in the dynamic table.