public void BuildRecipientSubstitutionStep_WithDisplayName(string address, string display)
        {
            var rec    = new MessageRecipient().ToAddress(address);
            var toStep =
                new MessageBuilder.BuildRecipientsStep.BuildToStep.BuildRecipientSubstitutionStep(
                    new MailerMessage().To(rec), rec);
            var stepBuilder = toStep.WithDisplayName(display);

            stepBuilder
            .Should()
            .NotBeNull()
            .And.BeOfType <MessageBuilder.BuildRecipientsStep.BuildToStep.BuiltToWithDisplayStep>()
            .Which.As <IBuilderContext>()
            .Message.Recipients
            .Should()
            .NotBeEmpty()
            .And.AllBeAssignableTo <MessageRecipient>()
            .And.Contain(r => r.DisplayName == display);
        }