private void AddToSortLayerList(ReorderableList list)
 {
     base.serializedObject.ApplyModifiedProperties();
     InternalEditorUtility.AddSortingLayer();
     base.serializedObject.Update();
     list.index = list.serializedProperty.arraySize - 1;
 }
 void AddToSortLayerList(ReorderableList list)
 {
     serializedObject.ApplyModifiedProperties();
     InternalEditorUtility.AddSortingLayer();
     serializedObject.Update();
     list.index = list.serializedProperty.arraySize - 1; // select just added one
 }