code: def unregister(cls, panel):
          
          success = Horizon.unregister_panel(cls, panel)
          if success:
              # Remove the panel's template directory.
              key = os.path.join(cls.slug, panel.slug)
              if key in loaders.panel_template_dirs:
                  del loaders.panel_template_dirs[key]
          return success
docs: Unregisters a :class:`~horizon.Panel` from this dashboard.