code: function() {
          if (this.options.removeBackBufferDelay === undefined) {
              this.removeBackBufferDelay = this.singleTile ? 0 : 2500;
          }
  
          if (this.options.className === undefined) {
              this.className = this.singleTile ? 'olLayerGridSingleTile' :
                                                 'olLayerGrid';
          }
      }
docs: Method: initProperties
  Set any properties that depend on the value of singleTile.
  Currently sets removeBackBufferDelay and className