code: function getFile(url) {
    const groupPattern = /~\d+\/nth\/\d+\//;
    const uploaded = url.startsWith(CDN_BASE_URL) && !groupPattern.test(url);
    return uploadcare.fileFrom(uploaded ? 'uploaded' : 'url', url);
  }
docs: Convert a single url to an Uploadcare file object wrapped in a promise-like
  object. Group urls that get passed here were not a part of a complete and
  untouched group, so they'll be uploaded as new images (only way to do it).