layer.descendants < array>

All descendant layers of this layer. These include layers that are nested multiple levels deep, so also the child layers of its own child layers. 译：这层的所有后代层。这些包括嵌套多个层次的层，所以也有自己的子层的子层。

layerA = new Layer

layerB = new Layer
    parent: layerA

layerC = new Layer
    parent: layerB

print layerA.descendants
# Output: [, ]