code: def layers(self):
      jlayers = callZooFunc(self.bigdl_type, "getSubModules", self)
      layers = [Layer.of(jlayer) for jlayer in jlayers]
      return layers
  
imports: import zoo.pipeline.api.autograd
  from zoo.feature.image import ImageSet
  from zoo.feature.text import TextSet
  from zoo.feature.common import FeatureSet
  from zoo.pipeline.api.keras.base import ZooKerasLayer
  from zoo.pipeline.api.keras.utils import *
  from bigdl.nn.layer import Layer
  from zoo.common.utils import callZooFunc
label_desc: Use image node_id 21 for calling the KerasNet obj's underlying member method code with example usage: obj.layers() and returns: layers