docs: def save_plots(self, directory, format="png", recommended_only=False):
          """
          Save images of dose-response curve-fits for each model.
  
          Parameters
          ----------
          directory : str
              Directory where the PNG files will be saved.
          format : str, optional
              Image output format. Valid options include: png, pdf, svg, ps, eps
          recommended_only : bool, optional
              If True, only recommended models for each session are included. If
              no model is recommended, then a row with it's ID will be included,
              but all fields will be null.
  
          Returns
          -------
          None
  
          """
          for i, session in enumerate(self):
              session.save_plots(
                  directory, prefix=str(i), format=format, recommended_only=recommended_only
              )