code: public final long getBeUint32() {
          if (position + 3 >= origin + limit) throw new IllegalArgumentException("limit excceed: "
                                                                                 + (position - origin + 3));
  
          byte[] buf = buffer;
          return ((long) (0xff & buf[position++]) << 24) | ((long) (0xff & buf[position++]) << 16)
                 | ((long) (0xff & buf[position++]) << 8) | ((long) (0xff & buf[position++]));
      }
docs: Return next 32-bit unsigned int from buffer. (big-endian)
  
  @see mysql-5.6.10/include/myisampack.h - mi_uint4korr