_set: function(x) {
x = clamp(x, this._minX, this._maxX);
this.targets.forEach(el => {
el.style.transform = 'translateX(' + x +'px)';
});
this._curX = x;
},
_updateDestination: function(x, duration) {
duration = duration != null ? duration : this.TRANSITION_DURATION;
this._startX = this._curX;
this._destX = clamp(x, this._minX, this._maxX);
var now = Date.now();
this._endTime = now + duration;
if (!this._requestId) {
this._startTime = now;
this._tween();
}
},