code: @Override
      public int getHeaderLength() {
          try {
              final byte b = this.headers.getByte(0);
              // length is encoded as the number of 32-bit words, so to get number of bytes we must multiply by 4
              return (b & 0x0F) * 4;
          } catch (final IOException e) {
              throw new RuntimeException("unable to get the header length of the IP packet due to IOException", e);
          }
      }
docs: The length of the ipv4 headers
  
  @return