Groovy implementation of a simplistic Iterative deepening depth-first search

iddfs.groovy

import groovy.transform.TailRecursive
import groovy.transform.ToString

@ToString(includePackage = false)
class Node<T> {
    T data
    List<Node<T>> nodes = []
}

final builder = new ObjectGraphBuilder(classLoader: getClass().classLoader)

final Node<String> root = builder.node(data: '1') {
    node(data: '2a') {
        node(data: '3a1')
        node(data: '3a2')
    }
    node(data: '2b') {
        node(data: '3a')
        node(data: '3b')
        node(data: '3c') {
            node(data: '4a')
        }
    }
}


def <T> boolean iddfs(Node<T> root, T item) {
    if (!root) {
        return true
    }

    final queue = new LinkedList<Node<T>>()
    queue.add(root)

    return iddfs_recursive(item, queue)
}

@TailRecursive
def static <T> boolean iddfs_recursive(T item, Queue<Node<T>> queue) {
    if (queue.isEmpty()) {
        return false
    }

    final first = queue.remove()

    if (first.data == item) {
        return true
    }

    queue.addAll(first.nodes)

    return iddfs_recursive(item, queue)
}

assert iddfs(root, '1')
assert iddfs(root, '2a')
assert iddfs(root, '2b')
assert iddfs(root, '3a')
assert iddfs(root, '3b')
assert iddfs(root, '3c')
assert iddfs(root, '4a')
assert !iddfs(root, 'dummy')