in cxx/fbjni/detail/CoreClasses-inl.h [288:297]
inline local_ref<R> JClass::newObject(
JConstructor<R(Args...)> constructor,
Args... args) const {
const auto env = Environment::current();
auto object = env->NewObject(self(), constructor.getId(),
detail::callToJni(
detail::Convert<typename std::decay<Args>::type>::toCall(args))...);
FACEBOOK_JNI_THROW_EXCEPTION_IF(!object);
return adopt_local(static_cast<R>(object));
}