code: function(rect) {
          if ( this.useCanvas ) {
              var context = this.context;
              context.save();
              context.lineWidth = 2 * $.pixelDensityRatio;
              context.strokeStyle = this.debugGridColor[0];
              context.fillStyle = this.debugGridColor[0];
  
              context.strokeRect(
                  rect.x * $.pixelDensityRatio,
                  rect.y * $.pixelDensityRatio,
                  rect.width * $.pixelDensityRatio,
                  rect.height * $.pixelDensityRatio
              );
  
              context.restore();
          }
      }
docs: private