docs: public final long getBeLong64(final int pos) {
          final int position = origin + pos;
  
          if (pos + 7 >= limit || pos < 0) throw new IllegalArgumentException("limit excceed: "
                                                                              + (pos < 0 ? pos : (pos + 7)));
  
          byte[] buf = buffer;
          return ((long) (0xff & buf[position + 7])) | ((long) (0xff & buf[position + 6]) << 8)
                 | ((long) (0xff & buf[position + 5]) << 16) | ((long) (0xff & buf[position + 4]) << 24)
                 | ((long) (0xff & buf[position + 3]) << 32) | ((long) (0xff & buf[position + 2]) << 40)
                 | ((long) (0xff & buf[position + 1]) << 48) | ((long) (buf[position]) << 56);
      }