layer.ancestors < array>

All ancestor layers of this layer. These include layers that are nested multiple levels deep, so also the parent layers of its own parent layer.
译：这层的所有原始层。这些包括嵌套的多个层次的层，所以也有自己的父层的父层。

layerA = new Layer

layerB = new Layer
    parent: layerA

layerC = new Layer
    parent: layerB

print layerC.ancestors
# Output: [, ]