set(key: string, value: string | number): void

import url from 'pts/url';

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

  params.set('key3', 'value3');
  params.set('key1', 1);
  
  // key1, 1
  // key2, value2
  // key3, value3
  for(var pair of params.entries()) {
    console.log(pair[0]+ ', '+ pair[1]);
  }
}