public void AddPdf_ThrowArgumentNullException()
        {
            // Act
            IWkHtmlSmartConvertBuilder act() => PdfConvertDependencyInjectionExtensions
            .AddPdf(_wkHtmlSmartConvertBuilder.Object, null);

            // Assert
            Assert.Throws <ArgumentNullException>(act);
        }
        public void AddPdf_AddsNeededServices()
        {
            // Act
            var builder = PdfConvertDependencyInjectionExtensions.AddPdf(_wkHtmlSmartConvertBuilder.Object);

            // Assert
            builder.Services.Should().NotBeEmpty();
            builder.Services.Should().ContainSingle(p => p.ServiceType == typeof(IPdfConvert));
        }