using System.Runtime.CompilerServices; namespace System.Collections.Concurrent { internal static class ConcurrentDictionaryExtensions { [System.Runtime.CompilerServices.NullableContext(1)] public static TValue GetOrAdd<[System.Runtime.CompilerServices.Nullable(2)] TKey, [System.Runtime.CompilerServices.Nullable(2)] TValue, [System.Runtime.CompilerServices.Nullable(2)] TArg>(this ConcurrentDictionary<TKey, TValue> dictionary, TKey key, Func<TKey, TArg, TValue> valueFactory, TArg factoryArgument) { if (dictionary.TryGetValue(key, out TValue value)) return value; return dictionary.GetOrAdd(key, valueFactory(key, factoryArgument)); } } }