public void push()
    {
        Map<String, Iterable<? extends WindupVertexFrame>> newFrame = new HashMap<>();
        deque.push(newFrame);
    }
public void push ( ) { Map < String , Iterable < ? extends WindupVertexFrame > > newFrame = new HashMap < > ( ) ; deque . push ( newFrame ) ; }
Add new {@link Variables} layer on top of the stack.