src/language-handlebars/printer-glimmer.js/printChildren
function printChildren(path, options, print) {
  return concat(
    path.map((childPath, childIndex) => {
      if (childIndex === 0) {
        return concat([softline, print(childPath, options, print)]);
      }

      return print(childPath, options, print);
    }, "children")
  );
}