code: def model_to_str(model):
      """
      Converts a Keras model to a string.
      :param model: a Keras model;
      :return: the output of `model.summary()` as a string;
      """
  
      def to_str(line):
          model_to_str.output += str(line) + "\n"
  
      model_to_str.output = ""
      model.summary(print_fn=lambda x: to_str(x))
      return model_to_str.output
  
imports: import os
  import time
  from pprint import pformat
label_desc: Use image node_id 5 for calling a global function with example usage: model_to_str(model) and returns: model_to_str