.
           * Set to true in order to prevent scroll from being constrained
           * to the dropdown when it opens.
           */
          allowOutsideScroll: {
            type: Boolean,
            value: false
          },

          /**
           * Whether focus should be restored to the button when the menu closes.
           */
          restoreFocusOnClose: {
            type: Boolean,
            value: true
          },

          /**
           * This is the element intended to be bound as 