<PackageReference Include="NUnit" Version="4.2.2" />

NUnit.Framework.Constraints.AttributeConstraint

AttributeConstraint tests that a specified attribute is present on a Type or other provider and that the value of the attribute satisfies some other constraint.
namespace NUnit.Framework.Constraints { public class AttributeConstraint : PrefixConstraint { public AttributeConstraint(Type type, IConstraint baseConstraint); } }