namespace System.Runtime.CompilerServices { [AttributeUsage(AttributeTargets.Class | AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Event | AttributeTargets.Parameter | AttributeTargets.ReturnValue | AttributeTargets.GenericParameter, Inherited = false)] public sealed class NullableAttribute : Attribute { /// Flags specifying metadata related to nullable reference types. public readonly byte[] NullableFlags; /// Initializes the attribute. /// The flags value. public NullableAttribute(byte value) { NullableFlags = new[] { value }; } /// Initializes the attribute. /// The flags value. public NullableAttribute(byte[] value) { NullableFlags = value; } } }