anchor.diff:  			 {"params", {struct, rpc_params(I, Data, Imports)}}]}},
        {reply, {struct, [{"json-rpc", "2.0"},
   		       {"id", ""},
  -		       {"result", {struct, rpc_params(O, Data, Imports)}}]}}}.
  +		       {"result",
  +			case O of
  +			    void -> void;
  +			    _ ->
  +				{struct, rpc_params(O, Data, Imports)}
  +			end}]}}}.
   
   
   rpc_params([{uses,_,G,_}|T], Data, Imports) ->
  
positive.code: each_module(_, [], _) ->
      [].
  
  to_json_rpc(Data, Dir, M) ->
      Imports = imports(Data, Dir),
      Data1 = augment(Data, Imports),
      lists:foldr(
        fun({rpc,_,N,InOut}, Acc) ->
  
negative.code: 
  mk_rpc_pair(InOut, N, Data, Imports) ->
      {_,_,_,I} = lists:keyfind(input, 1, InOut),
      O = case lists:keyfind(output, 1, InOut) of
  	    {_,_,_,Ox}  -> Ox;
  	    false -> void
  	end,
      {descr(InOut),
       {request, {struct, [{"json-rpc", "2.0"},
  			 {"method", N},
  