code: def import_plugin(name, superclasses=None):
      
      plugin_fqname = "sos.plugins.%s" % name
      if not superclasses:
          superclasses = (Plugin,)
      return import_module(plugin_fqname, superclasses)
docs: Import name as a module and return a list of all classes defined in that
      module. superclasses should be a tuple of valid superclasses to import,
      this defaults to (Plugin,).