internal static void SetUsed(this SISPlayableFrame playableFrame, bool used)
        {
#if UNITY_EDITOR
            bool prevUsed = playableFrame.IsUsed();
#endif

            playableFrame.SetBoolProperty(PlayableFramePropertyID.USED, used);

#if UNITY_EDITOR
            //Refresh
            if (used != prevUsed)
            {
                TimelineEditor.Refresh(RefreshReason.ContentsModified);
            }
#endif
        }
//----------------------------------------------------------------------------------------------------------------------

        internal static void SetLocked(this SISPlayableFrame playableFrame, bool used)
        {
            playableFrame.SetBoolProperty(PlayableFramePropertyID.LOCKED, used);
        }