VM.assert(VM.NOT_REACHED);
if (VM.VerifyAssertions) VM.assert(VM.NOT_REACHED);
  final void set(VM_StackBrowser browser, int instr) {      VM.assert(VM.NOT_REACHED);  }         /**   * Advance the VM_StackBrowser up one internal stack frame, if possible   */  final boolean up(VM_StackBrowser browser) {      return false;  }