get(key: string): null | string

import url from 'pts/url';

export default function() {
  const params = new url.URLSearchParams('key1=value1&key2=value2');

  const value1 = params.get('key1');
  console.log(value1); // value1
  const value3 = params.get('key3');
  console.log(value3); // null
}