in src/Reader.cc [100:112]
void Reader::SetListenerCallback(ReaderListenerCallback *listener) {
if (this->listener != nullptr) {
// It is only safe to set the listener once for the lifecycle of the Reader
return;
}
if (listener != nullptr) {
listener->reader = this;
// If a reader listener is set, the Reader instance is kept alive even if it goes out of scope in JS code.
this->Ref();
this->listener = listener;
}
}