how to use breath first search on binary tree?

i might be wrong but here is what i understand about breath first seach:
so if i use breath first search on tree below. I will get [5,2,7,1,3,8,9]
Code:
     
      5
    /   \
   2     7
  / \     \
 1   3     8
             \
              9



Code:
...
private class node {
		private String name;
		private int age;
		private node left_child;
		private node right_child;
...
}


/*** Breath-first search ***/
Code:
	public void breathFirstSearch(node root_node) {
		LinkedList<node> queue = new LinkedList<node>();

		if (root_node == null)
			System.out.println("empty");

		queue.add(root_node);
		while (!queue.isEmpty()) {
			node current = (node) queue.remove();
			if (current...) {
				...
			}
		}

	}