<PackageReference Include="System.Diagnostics.DiagnosticSource" Version="10.0.3" />

System.Diagnostics.CodeAnalysis.FeatureSwitchDefinitionAttribute

namespace System.Diagnostics.CodeAnalysis { internal sealed class FeatureSwitchDefinitionAttribute : Attribute { public string SwitchName { get; } public FeatureSwitchDefinitionAttribute(string switchName); } }