RReverser

async function supportsImgType(type) {
  // Create
  //
  // <picture>
  //   <source srcset="data:,x" type="{type}" />
  //   <img />
  // </picture>
  //
  // (where "data:,x" is just a minimal URL that is valid but doesn't trigger network)
  let img = document.createElement('img');