code: def _load_backend(backend_name):
      if backend_name in _loaded_backends:
          return _loaded_backends[backend_name]
      rv = _loaded_backends[backend_name] = backends[
          backend_name
      ].load()
      return rv
  
imports: import inspect
  import os
  import sys
  import warnings
  from functools import partial
  from importlib.metadata import entry_points
  import networkx
  from ..exception import NetworkXNotImplemented
label_desc: Use image node_id 2 for calling a global function with example usage: _load_backend(backend_name) and returns: rv, _loaded_backends