anchor.diff:      {error,{no_matching_fun_in_module,vmq_plugin_SUITE,nonexistent_fun,0}} =
           vmq_plugin_mgr:enable_module_plugin(hookname, ?MODULE, nonexistent_fun, 0).
   
  -module_plugin_mod_does_not_exist(Config) ->
  -    ok = write_config(Config ,empty_plugin_config()),
  +app_plugin_mod_does_not_exist(Config) ->
  +    ok = write_config(Config, empty_plugin_config()),
       {ok, _} = application:ensure_all_started(vmq_plugin),
  +    Hooks = [{nonexistent_mod,sample_hook,0}],
  +    application:set_env(vmq_plugin, vmq_plugin_hooks, Hooks),
       {error, {unknown_module,nonexistent_mod}} =
  -        vmq_plugin_mgr:enable_module_plugin(hookname, nonexistent_mod, sample_hook_function, 0).
  +        vmq_plugin_mgr:enable_plugin(vmq_plugin, [code:lib_dir(vmq_plugin)]).
  +
  +app_plugin_function_does_not_exist(Config) ->
  +    ok = write_config(Config, empty_plugin_config()),
  +    {ok, _} = application:ensure_all_started(vmq_plugin),
  +    Hooks = [{?MODULE,nonexistent_fun,0}],
  +    application:set_env(vmq_plugin, vmq_plugin_hooks, Hooks),
  +    {error, {no_matching_fun_in_module,vmq_plugin_SUITE,nonexistent_fun,0}} =
  +        vmq_plugin_mgr:enable_plugin(vmq_plugin, [code:lib_dir(vmq_plugin)]).
   
   sample_hook_function() ->
       ok.
  
positive.code:          cannot_enable_duplicate_module_plugin/1,
           cannot_enable_duplicate_app_plugin/1,
           module_plugin_mod_does_not_exist/1,
           module_plugin_function_does_not_exist/1]).
  
  -export([sample_hook_function/0,
           sample_hook_function/1,
  
negative.code:      cannot_enable_duplicate_module_plugin,
       cannot_enable_duplicate_app_plugin,
       module_plugin_mod_does_not_exist,
       module_plugin_function_does_not_exist,
       app_plugin_mod_does_not_exist,
       app_plugin_function_does_not_exist].
  
  init_per_suite(Config) ->
      application:ensure_all_started(lager),
  