in cxx/fbjni/detail/References.cpp [76:88]
bool isObjectRefType(jobject reference, jobjectRefType refType) {
// null-check first so that we short-circuit during (safe) global
// constructors, where we won't have an Environment::current() yet
if (!reference) {
return true;
}
static bool getObjectRefTypeWorks = doesGetObjectRefTypeWork();
return
!getObjectRefTypeWorks ||
Environment::current()->GetObjectRefType(reference) == refType;
}