code: function( state ) {
        if ( this.flipped === state ) {
          return this;
        }
  
        this.flipped = state;
        if(this.viewer.navigator){
          this.viewer.navigator.setFlip(this.getFlip());
        }
        this.viewer.forceRedraw();
  
        /**
         * Raised when flip state has been changed.
         *
         * @event flip
         * @memberof OpenSeadragon.Viewer
         * @type {object}
         * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
         * @property {Number} flipped - The flip state after this change.
         * @property {?Object} userData - Arbitrary subscriber-defined object.
         */
        this.viewer.raiseEvent('flip', {"flipped": state});
        return this;
      }
docs: Sets flip state according to the state input argument.
  @function
  @param {Boolean} state - Flip state to set.
  @return {OpenSeadragon.Viewport} Chainable.