public static Tuple <ImmutableList <ContractInputPredicate>, ImmutableList <ContractOutputPredicate <T> > > Ensures <T>( this Tuple <ImmutableList <ContractInputPredicate>, ImmutableList <ContractOutputPredicate <T> > > prev, ContractOutputPredicate <T> .ContractOutputPredicateDelegate pred, string message) => Tuple.Create(prev.Item1, prev.Item2.Add(new ContractOutputPredicate <T>(pred, message)));
public static Tuple <ImmutableList <ContractInputPredicate>, ImmutableList <ContractOutputPredicate <T> > > Ensures <T>(ContractOutputPredicate <T> .ContractOutputPredicateDelegate pred, string message) => Tuple.Create(ImmutableList <ContractInputPredicate> .Empty, ImmutableList <ContractOutputPredicate <T> > .Empty.Add(new ContractOutputPredicate <T>(pred, message)));