code: void zApplyGapBeforeButtonPixels() {
          int gapPixels = (gapBeforeButtonPixels == null) ? 3 : gapBeforeButtonPixels;
          ConstantSize gapSizeObject = new ConstantSize(gapPixels, ConstantSize.PIXEL);
          ColumnSpec columnSpec = ColumnSpec.createGap(gapSizeObject);
          FormLayout layout = ((FormLayout) parentDatePicker.getLayout());
          layout.setColumnSpec(2, columnSpec);
      }
docs: zApplyGapBeforeButtonPixels, This applies the named setting to the parent component.