         }];
            }
          },

          /**
           * An animation config. If provided, this will be used to animate the
           * closing of the dropdown.
           */
          closeAnimationConfig: {
            type: Object,
            value: function() {
              return [{
                name: 'fade-out-animation',
                timing: {
                  duration: 150
                }
              }, {
                name: 'paper-menu-shrink-width-animation',
           