private void addUpdateChildren(SafeArrayList<Spatial> results) {
        for (Spatial child : children.getArray()) {
            if (child.requiresUpdates()) {
                results.add(child);
            }
            if (child instanceof Node) {
                ((Node) child).addUpdateChildren(results);
            }
        }
    }
<code>getQuantity</code> returns the number of children this node
maintains.

@return the number of children this node maintains.
jme3-core/src/main/java/com/jme3/scene/Node.java