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

NUnit.Framework.Constraints.Constraint

public abstract class Constraint : IConstraint, IResolveConstraint
The Constraint class is the base of all built-in constraints within NUnit. It provides the operator overloads used to combine constraints.
namespace NUnit.Framework.Constraints { public abstract class Constraint : IConstraint, IResolveConstraint { public virtual string DisplayName { get; } public abstract string Description { get; } public object[] Arguments { get; } public ConstraintBuilder Builder { get; set; } public ConstraintExpression And { get; } public ConstraintExpression With { get; } public ConstraintExpression Or { get; } protected Constraint(params object[] args); public abstract ConstraintResult ApplyTo<[System.Runtime.CompilerServices.Nullable(2)] TActual>(TActual actual); public virtual ConstraintResult ApplyTo<[System.Runtime.CompilerServices.Nullable(2)] TActual>(ActualValueDelegate<TActual> del); public virtual ConstraintResult ApplyTo<[System.Runtime.CompilerServices.Nullable(2)] TActual>(ref TActual actual); protected virtual object GetTestObject<TActual>(ActualValueDelegate<TActual> del); protected string GetStringRepresentation(IEnumerable arguments); protected virtual string GetStringRepresentation(); public static Constraint operator &(Constraint left, Constraint right); public static Constraint operator |(Constraint left, Constraint right); public static Constraint operator !(Constraint constraint); public DelayedConstraint.WithRawDelayInterval After(int delay); public DelayedConstraint After(int delayInMilliseconds, int pollingInterval); } }