CTBorder ct = getCTBorder();
CTBorderPr pr = ct.isSetBottom() ? ct.getBottom() : ct.addNewBottom();
if(border == BORDER_NONE) ct.unsetBottom();
else pr.setStyle(STBorderStyle.Enum.forInt(border + 1));
int idx = _stylesSource.putBorder(new XSSFCellBorder(ct, _theme));
_cellXf.setBorderId(idx);
_cellXf.setApplyBorder(true);
}