anchor.diff:  
   -spec start_link(Module :: atom(), Port :: non_neg_integer()) ->
   	{ok, Pid :: pid()}
  -		| {error, Error :: already_present
  +		| {error, Reason :: already_present
   		| {already_started, Pid :: pid()} | term()}.
   %% @doc Start a RADIUS protocol server as part of a supervision tree
   %% 	 using the callback module `Module' listening on `Port'.
   %%
   start_link(Module, Port) ->
  -	{ok, Sup} = start(Module, Port),
  -	link(Sup),
  -	{ok, Sup}.
  +	case start(Module, Port) of
  +		{ok, Sup} ->
  +			link(Sup),
  +			{ok, Sup};
  +		{error, Reason} ->
  +			{error, Reason}
  +	end.
   
   -spec start_link(Module :: atom(), Port :: non_neg_integer(),
   		Address :: inet:ip_address()) ->
   	{ok, Pid :: pid()}
  -		| {error, Error :: already_present
  +		| {error, Reason :: already_present
   		| {already_started, Pid :: pid()} | term()}.
   %% @doc Start a RADIUS protocol server as part of a supervision tree
   %% 	using the callback module `Module' listening on `Port' with
   %% 	address `Address'.
   %%
   start_link(Module, Port, Address) ->
  -	{ok, Sup} = start(Module, Port, Address),
  -	link(Sup),
  -	{ok, Sup}.
  +	case start(Module, Port, Address) of
  +		{ok, Sup} ->
  +			link(Sup),
  +			{ok, Sup};
  +		{error, Reason} ->
  +			{error, Reason}
  +	end.
   
   -spec stop(Pid :: pid()) -> ok.
   %% @doc Stop a running RADIUS protocol server.
  
positive.code: 
  -spec start(Module :: atom(), Port :: non_neg_integer()) ->
  	{ok, Pid :: pid()}
  		| {error, Error :: already_present
  		| {already_started, Pid :: pid()} | term()}.
  %% @doc Start a RADIUS protocol server using the callback module
  %% 	`Module' listening on `Port'.
  
negative.code: -spec start(Module :: atom(), Port :: non_neg_integer(),
  		Address :: inet:ip_address()) ->
  	{ok, Pid :: pid()}
  		| {error, Reason :: already_present
  		| {already_started, Pid :: pid()} | term()}.
  %% @doc Start a RADIUS protocol server using the callback module
  %% 	`Module' listening on `Port' with address `Address'.
  