code: def __init__(self):
      if not self._loaded:
          load_modules = ["pydub"]
          self.backends = OrderedDict()
  
          for module in load_modules:
              self._import_backend(module)
  
          for backend, module in self.backends.items():
              if module is not None:
                  self.backend = backend
                  break
          else:
              try:
                  import scipy.io.wavfile
              except ImportError:
                  raise ImportError(
                      "No backend module is found. "
                      "At least you must install scipy in your environment."
                  )
  
          self._loaded = True
  
file_path: nnabla/python/src/nnabla/utils/audio_utils/backend_manager.py
imports: import importlib
  from collections import OrderedDict
label_desc: Use image node_id 2 to create a new AudioUtilsBackendManager object from inherited base classes: object with example: obj = AudioUtilsBackendManager()