code: def _set_persistent_module(mod):
      '''
      Add a module to loader.conf to make it persistent.
      '''
      if not mod or mod in mod_list(True) or mod not in \
              available():
          return set()
      __salt__['file.append'](_LOADER_CONF, _LOAD_MODULE.format(mod))
      return set([mod]f _set_persistent_module(mod):
      '''
      Add a module to loader.conf to make it persistent.
      '''
      if not mod or mod in mod_list(True) or mod not in \
              available():
          return set()
      __salt__['file.append'](_LOADER_CONF, _LOAD_MODULE.format(mod))
      return set([mod])
docs: Add a module to loader.conf to make it persistent.