using System.Runtime.CompilerServices; namespace System.Reactive.Linq.ObservableImpl { [System.Runtime.CompilerServices.NullableContext(1)] [System.Runtime.CompilerServices.Nullable(new byte[] { 0, 1 })] internal sealed class FirstBlocking<[System.Runtime.CompilerServices.Nullable(2)] T> : BaseBlocking<T> { public override void OnNext(T value) { if (!_hasValue) { _value = value; _hasValue = true; Set(); } } } }