add another stack node

src/Algorithms/Animated/BK/BlockCalc.java

@@ -21,7 +21,7 @@ public class BlockCalc implements AlgorithmStage {
 	private int r;
 	private LayeredGraphNode graph;
 	private ArrayList< ArrayList< ExtremalLayoutCalc > > subgraphAlgs;
-	private ArrayList< BackwardAction > backwards;
+	private ArrayList< BackwardAction > backwards; // TODO: evtl richtigen "Stack" benutzen
 	private LayoutType layout;
 	int step;