anchor.diff:      }
   
       if (!paramErrors.isEmpty) {
  -      completer.completeError(new core.ArgumentError(paramErrors.join(" / ")));
  -      return completer.future;
  +      throw new core.ArgumentError(paramErrors.join(" / "));
       }
   
   """);
  
positive.code:     }
  
      tmp.write("  $response $name(${params.join(", ")}) {\n");
      tmp.write("    var completer = new async.Completer();\n");
      tmp.write("    var url = \"${data["path"]}\";\n");
      if (upload) {
        tmp.write("    var uploadUrl = \"$uploadPath\";\n");
  
negative.code:       tmp.write("    response = ${noResource ? "this" : "_client"}.request(url, \"${data["httpMethod"]}\", $call);\n");
      }
  
      if (data.containsKey("response")) {
        tmp.write("    return response\n");
        tmp.write("      .then((data) => new ${data["response"]["\$ref"]}.fromJson(data));\n");
      } else {
        tmp.write("    return response;\n");
      }
      tmp.write("  }\n");
  
      return tmp.toString();
  