anchor.diff:      RpcMod = Context#context.rpc_mod,
       ImplMod = Context#context.impl_mod,
   
  +    % this field is initialized above by the known_content_type/2 function
  +    InputData = Context#context.request_body,
  +
       % make the actual call
       RpcResponse = RpcMod:rpc(ImplMod, FuncName, InputData, InputFormat, OutputFormat),
   
  
positive.code: % called for POST request
  known_content_type(ReqData, Context) ->
      ?PRINT(known_content_type),
      IsEmptyBody = (get_req_body(ReqData) =:= 'undefined'),
      IsKnownType =
          case wrq:get_req_header("content-type", ReqData) of
              "application/json" -> true;
              "application/xml" -> true;
              "application/x-protobuf" -> true;
              % allow content-type to be undefined when the body is empty
              'undefined' when IsEmptyBody -> true;
              _ -> false
          end,
      % otherwise, return 415 Unsupported media type
      {IsKnownType, ReqData, Context}.
  
  
  % Called for both GET and POST to find a match between provided content-types
  
negative.code: content_type_to_format(_) -> 'undefined'.
  
  
  set_data_response(Data, OutputFormat, ReqData) ->
      wrq:set_resp_header(
          "Content-Type", format_to_content_type(OutputFormat),
  