anchor.diff:  
   -export([do/1]).
   
  --include_lib("inets/include/httpd.hrl"). 
  +-include_lib("inets/include/httpd.hrl").
   
   -spec do(ModData) -> Result when
   	ModData :: #mod{},
  
positive.code: 	Fun :: fun((Arg) -> sent| close | Body),
  	Arg :: [term()].
  %% @doc Erlang web server API callback function.
  do(#mod{method = Method, entity_body = Body, data = Data} = _ModData) ->
  	case Method of
  		"POST" ->
  			case ocs_rest_res_subscriber:add_subscriber(Body) of
  				{error, ErrorCode} ->
  					{break, [{response,	{ErrorCode, "</h2>Erronous Request</h2>"}}]};
  				{Location, Response} ->
  					Head = [{code, 201}],
  					{break, [{response,{response, Head, Response}}]}
  
  			end;
  		_ ->
  			{proceed, Data}
  	end.
  
  
negative.code: 	NewData :: [{response,{StatusCode,Body}}] | [{response,{response,Head,Body}}]
  			| [{response,{already_sent,StatusCode,Size}}],
  	StatusCode :: integer(),
  	Body :: iolist() | nobody | {Fun, Arg},
  	Head :: [HeaderOption],
  	HeaderOption :: {Option, Value} | {code, StatusCode},
  	Option :: accept_ranges | allow
  