public E lower(E e)
    {
        if(root==null) return null;
        BstNode<E> checkable = root;
        E saved = null;
        while(checkable!=null)
        {
            if(checkable.element.compareTo(e) == 1 || checkable.element.compareTo(e) == 0)
            {
                if(checkable.left!=null)
                {
                    checkable = checkable.left;
                    continue;
                }
                return saved;
             }
             else
             {
                saved = checkable.element;
                if(checkable.right!=null)
                {
                    checkable = checkable.right;
                    continue;
                }
                return saved;
             }
        }
        return saved;
    }