namespace NUnit.Framework.Constraints { public abstract class PrefixConstraint : Constraint { protected IConstraint baseConstraint; protected string descriptionPrefix; public override string Description => string.Format((baseConstraint is EqualConstraint) ? "{0} equal to {1}" : "{0} {1}", descriptionPrefix, baseConstraint.Description); protected PrefixConstraint(IResolveConstraint baseConstraint) : base(baseConstraint) { Guard.ArgumentNotNull(baseConstraint, "baseConstraint"); this.baseConstraint = baseConstraint.Resolve(); } } }