code: private void obtainShowButtonBarDivider(@StyleRes final int themeResourceId) {
          TypedArray typedArray = getContext().getTheme().obtainStyledAttributes(themeResourceId,
                  new int[]{R.attr.materialDialogShowButtonBarDivider});
          showButtonBarDivider(typedArray.getBoolean(0, false));
      }
docs: Obtains, whether the divider, which is located above the dialog's buttons, should be shown,
  or not, from a specific theme.
  
  @param themeResourceId
  The resource id of the theme, the visibility should be obtained from, as an {@link
  Integer} value