Indices are based on order of horizontal graph traversal (bottom-up) and are 0-based.
get_layer(object, name = NULL, index = NULL)Keras model object
String, name of layer.
Integer, index of layer (0-based)
A layer instance.
Other model functions: compile,
  evaluate_generator, evaluate,
  fit_generator, fit,
  get_config,
  keras_model_sequential,
  keras_model, pop_layer,
  predict.tensorflow.keras.engine.training.Model,
  predict_generator,
  predict_on_batch,
  predict_proba,
  summary.tensorflow.keras.engine.training.Model,
  train_on_batch