ection_ = undefined;
  },

  attached() {
    // Save an instance of the controller since it's going to be used in
    // detached() where it can no longer be obtained.
    this.controller_ =
        tr.c.BrushingStateController.getControllerForElement(this);
  },

  detached() {
    // Reset highlights.
    this.clearHighlight_();
    this.controller_ = undefined;
  },

  set color(c) {
    this.style.color = c;
  },

  /**
   * @return {*|function():*}
   */
  get selection() {
    return this.selection_;