if (obj==null) throw new NullPointerException();
  private int get32Bits(Object obj) {    if (isStatic()) {      return VM_Statics.getSlotContentsAsInt(offset >>> LOG_BYTES_IN_INT);    } else {      if (obj==null)	throw new NullPointerException();      return VM_Magic.getIntAtOffset(obj, offset);    }  }