Cell cell = Context.getsmlObjectFactory().createCell();
CTXstringWhitespace ctx = Context.getsmlObjectFactory().createCTXstringWhitespace();
ctx.setValue(content);
CTRst ctrst = new CTRst();
ctrst.setT(ctx);
cell.setT(STCellType.INLINE_STR);
cell.setIs(ctrst); // add ctrst as inline string
return cell;