crossFadeFrom( fadeOutAction, duration, warp = false ) {

		fadeOutAction.fadeOut( duration );
		this.fadeIn( duration );

		if ( warp === true ) {

			const fadeInDuration = this._clip.duration,
				fadeOutDuration = fadeOutAction._clip.duration,

				startEndRatio = fadeOutDuration / fadeInDuration,
				endStartRatio = fadeInDuration / fadeOutDuration;

			fadeOutAction.warp( 1.0, startEndRatio, duration );
			this.warp( endStartRatio, 1.0, duration );

		}

		return this;

	}
Causes this action to fade in and the given action to fade out,
within the passed time interval.

@param {AnimationAction} fadeOutAction - The animation action to fade out.
@param {number} duration - The duration of the fade.
@param {boolean} [warp=false] - Whether warping should be used or not.
@return {AnimationAction} A reference to this animation action.