automatically generates new requests', function() {
          return new Promise(function(resolve) {
            ajax.addEventListener('request', function() {
              resolve();
            });
          });
        });

        test('does not send requests if url is not a string', function() {
          return new Promise(function(resolve, reject) {
            ajax.addEventListener('request', function() {
              reject('A request was generated but url is null!');
            });

            