function td(className) {
  const td = document.createElement("td");
  td.className = className;
  return td;
}
@localvoid:

There are two ways how to instantiate WebComponents: with a `new` operator and with `document.createElement()`
function. Instantiating WebComponents with a `new` operator has a slightly less overhead (probably because it
doesn't involve a hash map lookup to find a component).

The main reason why I've used `document.createElement()` here is because it is an idiomatic way to instantiate
components in all popular frameworks that use WebComponents.