Method expand

src/tree/model/node.js:211–233

(callback, expandParent)

  }

  expand(callback, expandParent) {
    const done = () => {
      if (expandParent) {
        let parent = this.parent;
        while (parent.level > 0) {
          parent.expanded = true;
          parent = parent.parent;
        }
      }
      this.expanded = true;
      if (callback) callback();
    };

    if (this.shouldLoadData()) {
      this.loadData((data) => {
        if (data instanceof Array) {
          done();
        }
      });
    } else {
      done();
    }
  }

  doCreateChildren(array, defaultProps = {}) {
    array.forEach((item) => {