UnityEditor.DragAndDrop.PrepareStartDrag C# (CSharp) Method

        public static void PrepareStartDrag()
        {
            ms_GenericData = null;
            PrepareStartDrag_Internal();
        }

 public override void StartDrag(TreeViewItem draggedNode, List <int> draggedNodes)
 {
     if (!EditorApplication.isPlaying)
     {
         List <AudioMixerItem> audioMixerItemsFromIDs = this.GetAudioMixerItemsFromIDs(draggedNodes);
         DragAndDrop.PrepareStartDrag();
         DragAndDrop.SetGenericData("AudioMixerDragging", new AudioMixerTreeViewDragging.DragData(audioMixerItemsFromIDs));
         string title = draggedNodes.Count + " AudioMixer" + ((draggedNodes.Count <= 1) ? "" : "s");
         DragAndDrop.StartDrag(title);
     }
 }