if let Some(tech_tree_node_entity) = tech_tree_node_entity {
            if let Some(current_tooltip) = self.current_tooltip {
                // only create if node entity has changed
                if current_tooltip != tech_tree_node_entity {
                    if let Some(container_node) = scene.get_node_for_entity(tech_tree_node_entity) {
                        let tooltip_node = create_tooltip::create(&entities, &mut color_storage, &mut rect_storage, &mut text_storage, &mut transform_storage, 0.0, 0.0);
                        self.current_tooltip = Some(tooltip_node.entity.unwrap().clone());
                        container_node.sub_nodes.push(tooltip_node);
                    }
                }
            }
        }
    }