Method get_node

src/jsmind.mind.js:35–42

* Get a node by id. * @param {string} node_id * @returns {Node | null}

(node_id)

     * @returns {Node | null}
     */
    get_node(node_id) {
        if (node_id in this.nodes) {
            return this.nodes[node_id];
        } else {
            logger.warn('the node[id=' + node_id + '] can not be found');
            return null;
        }
    }
    /**
     * Set the root node, only once.
     * @param {string} node_id