private void Update()
        {
            // Workaround so that CheckVarsUpdate() is invoked on Unity's main thread.
            // This is called by Unity on every frame.
            if (VarCache.VarsNeedUpdate && developerModeEnabled && Leanplum.HasStarted)
            {
                VarCache.CheckVarsUpdate();
            }

            // Run deferred actions.
            List <Action> actions = null;

            lock (delayed)
            {
                if (delayed.Count > 0)
                {
                    actions = new List <Action>(delayed);
                    delayed.Clear();
                }
            }
            if (actions != null)
            {
                foreach (Action action in actions)
                {
                    action();
                }
            }
        }
 /// <summary>
 ///     Forces content to update from the server. If variables have changed, the
 ///     appropriate callbacks will fire. Use sparingly as if the app is updated,
 ///     you'll have to deal with potentially inconsistent state or user experience.
 ///     The provided callback will always fire regardless
 ///     of whether the variables have changed.
 /// </summary>
 ///
 public override void ForceContentUpdate(Action callback)
 {
     VarCache.CheckVarsUpdate(callback);
 }