当不满足任何条件时，二进制搜索树中的contains方法如何返回false？

public class BinarySearchTree {
    private Node root;

    private class Node {
        private int value;
        private Node left;
        private Node right;

        public Node(int value) {
            this.value = value;
            this.left = null;
            this.right = null;
        }
    }

    public boolean contains(int target) {
        return contains(root, target);
    }

    private boolean contains(Node node, int target) {
        if (node == null) {
            return false;
        }

        if (node.value == target) {
            return true;
        }

        if (target < node.value) {
            return contains(node.left, target);
        } else {
            return contains(node.right, target);
        }
    }
}