in src/util/xml-helpers.js [349:355]
function textMatch (elm1, elm2) {
/** @param {et.ElementText | null} text */
const format = text => text ? String(text).replace(/\s+/, '') : '';
const text1 = format(elm1.text);
const text2 = format(elm2.text);
return (text1 === '' || text1 === text2);
}