Method append

src/tree/model/tree-store.js:93–99

(data, parentData)

  }

  append(data, parentData) {
    const parentNode = parentData ? this.getNode(parentData) : this.root;

    if (parentNode) {
      parentNode.insertChild({ data });
    }
  }

  _initDefaultCheckedNodes() {
    const defaultCheckedKeys = this.defaultCheckedKeys || [];