_noDefaultSelectedInheritsWidth() {
    if (this.checkedIndex === -1) {
      this._overlayCtrl.updateConfig({ inheritsReferenceWidth: 'min' });
    } else {
      this._overlayCtrl.updateConfig({
        inheritsReferenceWidth: this._initialInheritsReferenceWidth,
      });
    }
  }
With no selected element, we should override the inheritsReferenceWidth in most cases.
By default, we will set it to 'min', and then set it back to what it was initially when
something is selected.
As a subclasser you can override this behavior.
@protected