def stack(me, children)
      children = children.map{|c| c.is_a?(::Layers::LayerBase) ? c.to_node([]) : c}
      me.to_node(children)
    end
def stack(me, children)
      children = children.map{|c| c.is_a?(::Layers::LayerBase) ? c.to_node([]) : c}
      me.to_node(children)
    end
s methods for #to_json