public override void copyFrom(UITweener value)
        {
            base.copyFrom(value);

            UITweenRotation other = value as UITweenRotation;

            if (other != null)
            {
                this.from           = other.from;
                this.to             = other.to;
                this.quaternionLerp = other.quaternionLerp;
            }
        }
        /// <summary>
        /// Start the tweening operation.
        /// </summary>

        public static UITweenRotation Begin(GameObject go, float duration, Quaternion rot)
        {
            UITweenRotation comp = UITweener.Begin <UITweenRotation>(go, duration);

            comp.from = comp.value.eulerAngles;
            comp.to   = rot.eulerAngles;

            if (duration <= 0f)
            {
                comp.Sample(1f, true);
                comp.enabled = false;
            }
            return(comp);
        }