text: export default function load(src, cb) {
    const head = document.head || document.getElementsByTagName('head')[0];
    const script = document.createElement('script');
  
    script.type = 'text/javascript';
    script.async = true;
    script.src = src;
  
    if (cb) {
      script.onload = () => {
        script.onerror = null;
        script.onload = null;
        cb(null, script);
      };
      script.onerror = () => {
        script.onerror = null;
        script.onload = null;
        cb(new Error(`Failed to load ${src}`), script);
      };
    }
  
    head.appendChild(script);
  }
  