code: function ( message ) {
          this._hideMessage();
  
          var div = $.makeNeutralElement( "div" );
          div.appendChild( document.createTextNode( message ) );
  
          this.messageDiv = $.makeCenteredNode( div );
  
          $.addClass(this.messageDiv, "openseadragon-message");
  
          this.container.appendChild( this.messageDiv );
      }
docs: Display a message in the viewport
  @function OpenSeadragon.Viewer.prototype._showMessage
  @private
  @param {String} text message