public void CustomizeWithNullFixtureThrows()
 {
     // Fixture setup
     var sut = new RandomNumericSequenceCustomization();
     // Exercise system and verify outcome
     Assert.Throws<ArgumentNullException>(() =>
         sut.Customize(null));
     // Teardown
 }
 public void CustomizeAddsCorrectBuilderToFixture()
 {
     // Fixture setup
     var fixture = new Fixture();
     var sut = new RandomNumericSequenceCustomization();
     // Exercise system
     sut.Customize(fixture);
     var result = fixture.Customizations
         .OfType<RandomNumericSequenceGenerator>()
         .SingleOrDefault();
     // Verify outcome
     Assert.NotNull(result);
     // Teardown
 }