VM_Interface._assert(workDequeue.pop().isZero());
VM_Interface._assert(workDeque.pop().isZero());
  private final void collectWhite(VM_Address object)    throws VM_PragmaInline {    if (VM_Interface.VerifyAssertions)      VM_Interface._assert(workDequeue.pop().isZero());    while (!object.isZero()) {      if (RCBaseHeader.isWhite(object) && !RCBaseHeader.isBuffered(object)) {	RCBaseHeader.makeBlack(object);	ScanObject.enumeratePointers(object, collectEnum);	freeBuffer.push(object);      }      object = workDequeue.pop();    }  }