code: def register_keras_layer_handler(layer_cname, handler_func):
      """Register a handler function for the given layer class name.
  
      The handler function should have the following signature:
          parse_func(keras_layer, input_names, input_shapes, data_reader, config):
  
      Args:
          layer_cname (str): The name of Keras layer (the 'class_name' property in the layer's config)
          handler_func (callable): The handler function
  
      Raises:
          Exception: If the layer class has already been registered.
      """
      if layer_cname in layer_handlers:
          raise Exception(f"Layer {layer_cname} already registered")
      else:
          layer_handlers[layer_cname] = handler_func
  
imports: import json
  import h5py
  from hls4ml.model import ModelGraph
label_desc: Use image node_id 2 for calling a global function with example usage: register_keras_layer_handler(layer_cname, handler_func) without return types