code: def dynamic_import_st(module, backend):
      """Import ST models dynamically.
  
      Args:
          module (str): module_name:class_name or alias in `predefined_st`
          backend (str): NN backend. e.g., pytorch, chainer
  
      Returns:
          type: ST class
  
      """
      model_class = dynamic_import(
          module, predefined_st.get(backend, dict())
      )
      assert issubclass(
          model_class, STInterface
      ), f"{module} does not implement STInterface"
      return model_class
  
imports: from espnet.nets.asr_interface import ASRInterface
  from espnet.utils.dynamic_import import dynamic_import
label_desc: Use image node_id 1 for calling a global function with example usage: dynamic_import_st(module, backend) and returns: model_class