/// <summary>
        /// Tab that offers prefab merging.
        /// </summary>
        private void OnGUIPrefabTab()
        {
            GameObject prefab;

            if (!mergeInProgress)
            {
                GUILayout.Label("Drag your prefab here to start merging:");
                if (prefab = EditorGUILayout.ObjectField(null, typeof(GameObject), false, GUILayout.Height(60)) as GameObject)
                {
                    var mm = new MergeManagerPrefab(this, vcs);
                    if (mm.InitializeMerge(prefab))
                    {
                        manager = mm;
                    }
                }
            }

            DisplayMergeProcess();
        }
        /// <summary>
        /// Tab that offers prefab merging.
        /// </summary>
        private void OnGUIPrefabTab()
        {
            GameObject prefab;
            if(!mergeInProgress)
            {
                GUILayout.Label("Drag your prefab here to start merging:");
                if(prefab = EditorGUILayout.ObjectField(null, typeof(GameObject), false, GUILayout.Height(60)) as GameObject)
                {
                    var mm = new MergeManagerPrefab(this, vcs);
                    if(mm.InitializeMerge(prefab))
                    {
                        manager = mm;
                    }
                }
            }

            DisplayMergeProcess();
        }