highlight (node) {
    if (this.locked) {
      return
    }

    if (this.node !== node) {
      // unhighlight current node
      if (this.node) {
        this.node.setHighlight(false)
      }

      // highlight new node
      this.node = node
      this.node.setHighlight(true)
    }

    // cancel any current timeout
    this._cancelUnhighlight()
  }
Hightlight given node and its childs
@param {Node} node