private void InitDB()
 {
     if (_searchDB == null)
     {
         _searchDB = new PrefabSearchDB();
     }
 }
        private void DrawSettings()
        {
            DrawSeparator();

            EditorGUILayout.LabelField("Preferences:", EditorStyles.boldLabel);
            selectAllByDefault = EditorGUILayout.Toggle("Select All by default:", selectAllByDefault, GUILayout.Width(200));
            saveAssetsOnApply  = EditorGUILayout.Toggle("Save on apply (slower):", saveAssetsOnApply, GUILayout.Width(200));
            if (GUILayout.Button("Refresh DB", GUILayout.Height(25), GUILayout.Width(90)))
            {
                _searchDB = null;
                InitDB();
            }
        }