code: private boolean checkSingleColumnEditorDisabled() {
          final int size = listEditor.getList().size();
          final boolean hasEditors = !listEditor.getEditors().isEmpty();
          if (size == 1 && hasEditors) {
              setEditorEnabled(0 ,false, DataSetEditorConstants.INSTANCE.dataSetMustHaveAtLeastOneColumn());
              return true;
          }
          return false;
      }
docs: Checks that if only single column used in data set -> it cannot be unselected.