<PackageReference Include="Serilog.Sinks.EventLog" Version="4.0.1-dev-00087" />

System.Diagnostics.CodeAnalysis.DisallowNullAttribute

Specifies that null is disallowed as an input even if the corresponding type allows it.
namespace System.Diagnostics.CodeAnalysis { internal sealed class DisallowNullAttribute : Attribute { public DisallowNullAttribute(); } }