Some possible optimization

src/main/java/it/unipr/analysis/AbstractStackSet.java

@@ -54,21 +54,7 @@ public boolean isBottom() {
 	public int size() {
 		return this.elements().size();
 	}
-
-	@Override
-	public AbstractStackSet clone() {
-		if (isTop())
-			return TOP;
-		else if (isBottom())
-			return BOTTOM;
-		return new AbstractStackSet(new HashSet<>(this.elements), false);
-
-//		AbstractStackSet result = new AbstractStackSet(new HashSet<AbstractStack>(), false);
-//		for (AbstractStack stack : elements())
-//			result.add(stack.clone());
-//		return result;
-	}
-
+
 	@Override
 	public AbstractStackSet lubAux(AbstractStackSet other) throws SemanticException {
 		AbstractStackSet lubAux = super.lubAux(other);

src/main/java/it/unipr/analysis/EVMAbstractState.java

@@ -99,7 +99,7 @@ public EVMAbstractState(AbstractStackSet stacks, Memory memory, Memory storage,
 	 * @return A cloned copy of the stack or null if the original stack is null.
 	 */
 	public AbstractStackSet getStacks() {
-		return stacks.clone();
+		return stacks;
 	}
 
 	/**
@@ -1925,31 +1925,31 @@ public boolean isEmpty() {
 
 	@Override
 	public EVMAbstractState wideningAux(EVMAbstractState other) throws SemanticException {
-		return new EVMAbstractState(stacks.widening(other.getStacks()),
+		return new EVMAbstractState(stacks.widening(other.stacks),
 				memory.widening(other.getMemory()),
 				storage.widening(other.storage),
 				mu_i.widening(other.getMu_i()));
 	}
 
 	@Override
 	public EVMAbstractState lubAux(EVMAbstractState other) throws SemanticException {
-		return new EVMAbstractState(stacks.lubAux(other.getStacks()),
+		return new EVMAbstractState(stacks.lubAux(other.stacks),
 				memory.lub(other.getMemory()),
 				storage.lub(other.storage),
 				mu_i.lub(other.getMu_i()));
 	}
 
 	@Override
 	public EVMAbstractState glbAux(EVMAbstractState other) throws SemanticException {
-		return new EVMAbstractState(stacks.glbAux(other.getStacks()),
+		return new EVMAbstractState(stacks.glbAux(other.stacks),
 				memory.glb(other.getMemory()),
 				storage.glb(other.storage),
 				mu_i.glb(other.getMu_i()));
 	}
 
 	@Override
 	public boolean lessOrEqualAux(EVMAbstractState other) throws SemanticException {
-		return stacks.lessOrEqual(other.getStacks()) &&
+		return stacks.lessOrEqual(other.stacks) &&
 				memory.lessOrEqual(other.getMemory()) &&
 				mu_i.lessOrEqual(other.getMu_i());
 	}