public void It_should_throw_exception()
        {
            // ARRANGE
            var builder = Fixture.DbContextBuilder;
            var entity = new Customer();					// not of type EntityTypeConfiguration and of non-generic
            var baseType = entity.GetType().BaseType;

            // ASSERT
            var exception = Assert.Throws<InvalidOperationException>(() =>
            {
                // ACT
                var result = builder.IsMappingClass(baseType);
            });
            Assert.AreEqual("This operation is only valid on generic types.", exception.Message);
        }