<PackageReference Include="System.Configuration.ConfigurationManager" Version="4.6.0-preview6.19264.9" />

NullableAttribute

sealed class NullableAttribute : Attribute
using Microsoft.CodeAnalysis; namespace System.Runtime.CompilerServices { [CompilerGenerated] [Microsoft.CodeAnalysis.Embedded] internal sealed class NullableAttribute : Attribute { public readonly byte[] NullableFlags; public NullableAttribute(byte P_0) { NullableFlags = new byte[1] { P_0 }; } public NullableAttribute(byte[] P_0) { NullableFlags = P_0; } } }