<PackageReference Include="NUnit" Version="4.3.0" />

IAsyncConstraint

Interface for constraints which support asynchrnious ApplyAsync.
using System; using System.Runtime.CompilerServices; using System.Threading.Tasks; namespace NUnit.Framework.Constraints { internal interface IAsyncConstraint : IConstraint, IResolveConstraint { [System.Runtime.CompilerServices.NullableContext(1)] Task<ConstraintResult> ApplyToAsync<[System.Runtime.CompilerServices.Nullable(2)] TActual>(Func<Task<TActual>> delTask); } }