return place ? ::new (place) nsXBLAttributeEntry(aSrcAtom, aDstAtom, aContent) : nsnull;
return place ? ::new (place) nsXBLAttributeEntry(aSrcAtom, aDstAtom, aDstNameSpace, aContent) : nsnull;
  Create(nsIAtom* aSrcAtom, nsIAtom* aDstAtom, nsIContent* aContent) {    void* place = nsXBLPrototypeBinding::kAttrPool->Alloc(sizeof(nsXBLAttributeEntry));    return place ? ::new (place) nsXBLAttributeEntry(aSrcAtom, aDstAtom, aContent) : nsnull;  }