layer.shadowBlur < number>

Adds a Gaussian blur to the shadowX or shadowY property. shadowBlur is defined with a number. The default value is 0.
译：添加一个高斯模糊shadowX或阴影的属性。shadowBlur定义是一个数字。默认值是0。

layerA = new Layer
layerA.shadowY = 1
layerA.shadowBlur = 4