$destructors * @param non-empty-list $instruments * @psalm-suppress PossiblyNullArgument,PossiblyNullPropertyAssignment,PossiblyNullPropertyFetch */ public static function observe( MetricWriterInterface $writer, ArrayAccess $destructors, callable $callback, array $instruments, ReferenceCounterInterface $referenceCounter, ): ObservableCallbackInterface { $target = null; $callback = weaken(closure($callback), $target); $callbackId = $writer->registerCallback($callback, ...$instruments); $referenceCounter->acquire(); $destructor = null; if ($target) { $destructor = $destructors[$target] ??= new ObservableCallbackDestructor($destructors, $writer); $destructor->callbackIds[$callbackId] = $referenceCounter; } return new ObservableCallback($writer, $referenceCounter, $callbackId, $destructor, $target); } }