g the overlay with the ESC key.
       */
      noCancelOnEscKey: {
        type: Boolean,
        value: false
      },

      /**
       * Set to true to disable canceling the overlay by clicking outside it.
       */
      noCancelOnOutsideClick: {
        type: Boolean,
        value: false
      },

      /**
       * Returns the reason this dialog was last closed.
       */
      closingReason: {
        // was a getter before, but needs to be a property so other
        // behaviors can override this