onTransitionEnd_({propertyName = ''}) {
        // Detect whether transition may affect dimensions of an element.
        const isReflowProperty = transitionKeys.some(key => {
            return !!~propertyName.indexOf(key);
        });

        if (isReflowProperty) {
            this.refresh();
        }
    }
"Transitionend" event handler.

@private
@param {TransitionEvent} event
@returns {void}