public bool Merge(IMemento otherMemento) { DrawableContainerBoundsChangeMemento other = otherMemento as DrawableContainerBoundsChangeMemento; if (other != null) { if (Objects.CompareLists <IDrawableContainer>(listOfdrawableContainer, other.listOfdrawableContainer)) { // Lists are equal, as we have the state already we can ignore the new memento return(true); } } return(false); }