code: private void obtainDividerMargin(@StyleRes final int themeResourceId) {
          TypedArray typedArray = getContext().getTheme().obtainStyledAttributes(themeResourceId,
                  new int[]{R.attr.materialDialogDividerMargin});
          setDividerMargin(typedArray.getDimensionPixelSize(0, 0));
      }
docs: Obtains the left and right margin of dividers from a specific theme.
  
  @param themeResourceId
  The resource id of the theme, the margin should be obtained from, as an {@link
  Integer} value