code: def _process_panel_configuration(self, config):
          
          try:
              dashboard = config.get('PANEL_DASHBOARD')
              if not dashboard:
                  LOG.warning("Skipping %s because it doesn't have "
                              "PANEL_DASHBOARD defined.", config.__name__)
                  return
              panel_slug = config.get('PANEL')
              dashboard_cls = self.get_dashboard(dashboard)
              panel_group = config.get('PANEL_GROUP')
              default_panel = config.get('DEFAULT_PANEL')
  
              # Set the default panel
              if default_panel:
                  dashboard_cls.default_panel = default_panel
  
              # Remove the panel
              if config.get('REMOVE_PANEL', False):
                  for panel in dashboard_cls.get_panels():
                      if panel_slug == panel.slug:
                          dashboard_cls.unregister(panel.__class__)
              elif config.get('ADD_PANEL', None):
                  # Add the panel to the dashboard
                  panel_path = config['ADD_PANEL']
                  mod_path, panel_cls = panel_path.rsplit(".", 1)
                  try:
                      mod = import_module(mod_path)
                  except ImportError as e:
                      LOG.warning("Could not import panel module %(module)s: "
                                  "%(exc)s", {'module': mod_path, 'exc': e})
                      return
                  panel = getattr(mod, panel_cls)
                  # test is can_register method is present and call method if
                  # it is to determine if the panel should be loaded
                  if hasattr(panel, 'can_register') and \
                     callable(getattr(panel, 'can_register')):
                      if not panel.can_register():
                          LOG.debug("Load condition failed for panel: %(panel)s",
                                    {'panel': panel_slug})
                          return
                  dashboard_cls.register(panel)
                  if panel_group:
                      dashboard_cls.get_panel_group(panel_group).\
                          panels.append(panel.slug)
                  else:
                      panels = list(dashboard_cls.panels)
                      panels.append(panel)
                      dashboard_cls.panels = tuple(panels)
          except Exception as e:
              LOG.warning('Could not process panel %(panel)s: %(exc)s',
                          {'panel': panel_slug, 'exc': e})
docs: Add, remove and set default panels on the dashboard.