code: def plot_pr_curves(
      precisions,
      recall,
      classes,
      thresholds=None,
      backend="plotly",
      **kwargs,
  ):
      """Plots a set of per-class precision-recall (PR) curves.
  
      Args:
          precisions: a ``num_classes x num_recalls`` array-like of per-class
              precision values
          recall: an array-like of recall values
          classes: the list of classes
          thresholds (None): an ``num_classes x num_recalls`` array-like of
              decision thresholds
          backend ("plotly"): the plotting backend to use. Supported values are
              ``("plotly", "matplotlib")``
          **kwargs: keyword arguments for the backend plotting method:
  
              -   "plotly" backend: :meth:`fiftyone.core.plots.plotly.plot_pr_curves`
              -   "matplotlib" backend: :meth:`fiftyone.core.plots.matplotlib.plot_pr_curves`
  
      Returns:
          one of the following
  
          -   a :class:`fiftyone.core.plots.plotly.PlotlyNotebookPlot`, if you
              are working in a Jupyter notebook and the plotly backend is used
          -   a plotly or matplotlib figure, otherwise
      """
      backend = _parse_backend(backend)
  
      if backend == "matplotlib":
          from .matplotlib import plot_pr_curves as _plot_pr_curves
  
          if thresholds is not None:
              logger.warning(
                  "Ignoring unsupported argument `thresholds` for the "
                  "'matplotlib' backend"
              )
      else:
          from .plotly import plot_pr_curves as _plot_pr_curves
  
          kwargs.update(dict(thresholds=thresholds))
  
      return _plot_pr_curves(precisions, recall, classes, **kwargs)
  
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 4 for calling a global function with example usage: plot_pr_curves(precisions, recall, classes, thresholds, backend) and returns: _plot_pr_curves