code: def _parse_backend(backend):
      if backend is None:
          return "plotly"
  
      available_backends = ("matplotlib", "plotly")
      if backend not in available_backends:
          raise ValueError(
              "Unsupported plotting backend '%s'; supported values are %s"
              % (backend, available_backends)
          )
  
      return backend
  
imports: import logging
  import fiftyone.core.context
  import fiftyone.core.labels
  import fiftyone.core.patches
  import fiftyone.core.video
label_desc: Use image node_id 9 for calling a global function with example usage: _parse_backend(backend) and returns: backend, str