in chime-sdk-signaling-cpp/src/signaling/default_signaling_client.cc [343:347]
void DefaultSignalingClient::RemoveSignalingClientObserver(SignalingClientObserver* observer) {
auto observer_found = std::find(observers_.cbegin(), observers_.cend(), observer);
if (observer_found == observers_.cend()) return;
observers_.erase(observer_found);
}