final NewNestedInterfaceType asyncServiceInterface = newType.newNestedInterfaceType();
asyncServiceInterface.setNestedName(Constants.RPC_ASYNC_SERVICE_INTERFACE);
asyncServiceInterface.setStatic(true);
asyncServiceInterface.setVisibility(Visibility.PUBLIC);
final NewMethod newMethod = asyncServiceInterface.newMethod();
newMethod.setAbstract(true);
newMethod.setFinal(false);
newMethod.setName(Constants.PAYLOAD_DECLARATION_METHOD);
newMethod.setNative(false);
newMethod.setReturnType(context.getVoid());