anchor.diff:           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]).
  +         module_plugin_function_does_not_exist/1,
  +         app_plugin_mod_does_not_exist/1,
  +         app_plugin_function_does_not_exist/1]).
   
   -export([sample_hook_function/0,
            sample_hook_function/1,
  
positive.code:     {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()),
      {ok, _} = application:ensure_all_started(vmq_plugin),
      {error, {unknown_module,nonexistent_mod}} =
          vmq_plugin_mgr:enable_module_plugin(hookname, nonexistent_mod, sample_hook_function, 0).
  
  sample_hook_function() ->
      ok.
  
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),
  