docstr: Only works for the sequential model.
          
docstr_tok: ["Only","works","for","the","sequential","model","."]
code: def get_layer_output_function(self, layer_num):
      """Only works for the sequential model."""
  
      return K.function(
          [self.model.layers[0].input],
          [self.model.layers[layer_num].output],
      )
  
imports: from keras.engine import Input, Model
  from keras.layers import Activation, Lambda
  from keras.layers.merge import concatenate
  from keras.optimizers import Nadam, SGD, Adam, RMSprop, Adagrad, Adamax, Adadelta
  from keras import backend
  from deepneuro.models.cost_functions import dice_coef_loss, dice_coef
  from deepneuro.models.model import DeepNeuroModel
  from deepneuro.utilities.visualize import check_data
  from deepneuro.utilities.util import add_parameter
  from deepneuro.models.callbacks import get_callbacks
  from deepneuro.models.cost_functions import WeightedCategoricalCrossEntropy
label_desc: Use image node_id 7 for calling the KerasModel obj's underlying member method code with example usage: obj.get_layer_output_function(layer_num) and returns: K