functions.add('test', function test() {
  const transparentPng =
    'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAA1JREFUGFdjYGD4/x8AAwIB/8myre4AAAAASUVORK5CYII='
  return `url(${transparentPng})`
})
