Indices are based on order of horizontal graph traversal (bottom-up) and are
1-based. If name and index are both provided, index will take
precedence.
get_layer(object, name = NULL, index = NULL)Keras model object
String, name of layer.
Integer, index of layer (1-based)
A layer instance.
Other model functions: 
compile.keras.engine.training.Model(),
evaluate.keras.engine.training.Model(),
evaluate_generator(),
fit.keras.engine.training.Model(),
fit_generator(),
get_config(),
keras_model_sequential(),
keras_model(),
multi_gpu_model(),
pop_layer(),
predict.keras.engine.training.Model(),
predict_generator(),
predict_on_batch(),
predict_proba(),
summary.keras.engine.training.Model(),
train_on_batch()