anchor.diff:  
   %% @spec new(Mod:: atom() | list(atom())) -> ok
   %% @equiv new(Mod, [])
  --spec new(Mod:: atom() | list(atom())) -> ok.
  +-spec new(Mod:: atom() | [atom()]) -> ok.
   new(Mod) when is_atom(Mod) -> new(Mod, []);
   new(Mod) when is_list(Mod) -> [new(M) || M <- Mod], ok.
   
  
positive.code: %% (function clause) or unexpected exceptions.
  %%
  %% Use the {@link history/1} function to analyze errors.
  -spec validate(Mod:: atom() | list(atom())) -> boolean().
  validate(Mod) when is_atom(Mod) ->
      call(Mod, validate);
  validate(Mod) when is_list(Mod) ->
  
negative.code: %%
  %% The function returns the list of mocked modules that were unloaded
  %% in the process.
  -spec unload() -> [atom()].
  unload() -> lists:foldl(fun unload_if_mocked/2, [], registered()).
  
  %% @spec unload(Mod:: atom() | list(atom())) -> ok
  