anchor.diff:  %%==========================================================================================
   -spec(caller_called_modules(FName::filename(), SearchPaths::[dir()], TabWidth::integer()) -> ok).
   caller_called_modules(FName, SearchPaths, _TabWidth) ->
  +    check_search_paths(FName, SearchPaths),
       %% I use 'false' in the following function call, so that macro can get expanded;
       AbsFileName = filename:absname(filename:join(filename:split(FName))),
       ClientFiles = wrangler_modulegraph_server:get_client_files(AbsFileName, SearchPaths),
  
positive.code: 
  -spec(non_tail_recursive_servers_in_file(FName::filename(), SearchPaths::[dir()], TabWidth::integer()) -> ok).
  non_tail_recursive_servers_in_file(FName, SearchPaths, TabWidth) ->
      Funs = non_tail_recursive_servers(FName, SearchPaths, TabWidth),
      non_tail_format_results(Funs).
   
  -spec(non_tail_recursive_servers_in_dirs(SearchPaths::[dir()], TabWidth::integer()) -> ok).
  non_tail_recursive_servers_in_dirs(SearchPaths, TabWidth) ->
      Files = refac_util:expand_files(SearchPaths, ".erl"),
      Funs = lists:flatmap(fun(F) ->
  				 non_tail_recursive_servers(F, SearchPaths, TabWidth)
  
negative.code:      wrangler_callgraph_server:fun_callgraph_to_dot(OutFile, FileName).
     
  
  check_search_paths(FileName, SearchPaths) ->
      InValidSearchPaths = lists:filter(fun (X) -> not filelib:is_dir(X) end, SearchPaths),
      case InValidSearchPaths of
  	[] -> ok;
  	_ -> ?wrangler_io("\n===============================WARNING===============================\n",[]), 
  	     ?wrangler_io("The following directories specified in the search paths do not exist:\n~s", [InValidSearchPaths]),
  	     throw({error, "Some directories specified in the search paths do not exist!"})
      end,
      Files = refac_util:expand_files(SearchPaths, ".erl") ++
  	 refac_util:expand_files(SearchPaths, ".hrl"),
      case lists:member(FileName, Files) of
  	true ->
  	    ok;
  	_ ->
      	    throw({error, "The current Erlang file does not belong to any of the search paths specified; please check!"})
      end.
  
  
  	
  
  
  
  
   
  