+ r = sd_bus_message_peek_type(m, &type, &signature);
+ if (r < 0)
+ return r;
+
+ if (type != 'v' || !streq(strempty(signature), strempty(c->vtable->x.property.signature)))
+ return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_ARGS, "Incorrect parameters for property '%s', expected '%s', got '%s'.", c->member, strempty(c->vtable->x.property.signature), strempty(signature));
+