code: def _plugin_get(self, plugin_name):
          
          if not plugin_name:
              return None, u"Plugin name not set"
          for plugin in self.controller.plugins:
              if not isinstance(plugin, SettablePlugin):
                  continue
              if plugin.name == plugin_name:
                  return plugin, ""
          return None, u"Settable plugin '{}' not found".format(plugin_name)
docs: Find plugins in controller
  
          :param plugin_name: Name of the plugin to find
          :type plugin_name: str | None
          :return: Plugin or None and error message
          :rtype: (settable_plugin.SettablePlugin | None, str)