next = function() {
    index++;
    if (index < result['scripts'].length) {
      var item = result['scripts'][index];
      var fn = function() {};
      if (item.url) {
        if (item.name) {
          fn = spf.bind(spf.net.script.load, null, item.url, item.name);
        } else {
          fn = spf.bind(spf.net.script.get, null, item.url);
        }
      } else if (item.text) {
        if (item.name) {
          fn = spf.bind(spf.net.script.eval, null, item.text, item.name);
        } else {
          fn = spf.bind(spf.net.script.exec, null, item.text);
        }
      }
      if (item.url && !item.async) {
        fn(next);
      } else {
        fn();
        next();
      }
    } else {
      opt_callback && opt_callback();
    }
  }
Installs scripts that have been extracted from an HTML string.
See {@link spf.net.script.load}, {@link spf.net.script.eval}, and
{@link #extract_}.

@param {!spf.nav.response.Extraction_} result The extraction result.
@param {Function=} opt_callback Callback function to execute after
    all scripts are loaded.
@private