function parseUrl(url) {
	  var lastSlash = url.lastIndexOf('/');
	  var lastSearchParam = url.lastIndexOf('?');
	  var prefix = url.substring(0, lastSlash);
	  var suffix = lastSearchParam > lastSlash ? url.substring(lastSearchParam) : '';
	  return [prefix + '/', suffix];
	}
Extract the prefix and suffix of the url, where the prefix is the path before
the last file, and suffix is the search params after the last file.
```
const url = 'http://tfhub.dev/model/1/tensorflowjs_model.pb?tfjs-format=file'
[prefix, suffix] = parseUrl(url)
// prefix = 'http://tfhub.dev/model/1/'
// suffix = '?tfjs-format=file'
```
@param url the model url to be parsed.