code: def import_extension_module(ext_name):
      """
      Import an extension module by name.
  
      The extension modules are installed under the `nnabla_ext` package as
      namespace packages. All extension modules provide a unified set of APIs.
  
      Args:
          ext_name(str): Extension name. e.g. 'cpu', 'cuda', 'cudnn' etc.
  
      Returns: module
          An Python module of a particular NNabla extension.
  
      Example:
  
          .. code-block:: python
  
              ext = import_extension_module('cudnn')
              available_devices = ext.get_devices()
              print(available_devices)
              ext.device_synchronize(available_devices[0])
              ext.clear_memory_cache()
  
      """
      import importlib
  
      try:
          return importlib.import_module("." + ext_name, "nnabla_ext")
      except ImportError as e:
          from nnabla import logger
  
          logger.error(
              "Extension `{}` does not exist.".format(ext_name)
          )
          raise e
  
label_desc: Use image node_id 1 for calling a global function with example usage: import_extension_module(ext_name) and returns: importlib