public void WithEmptyFallback_Invoke_Success()
{
OneToOneMap <string> propertyMapping = Map(t => t.Value);
Assert.Same(propertyMapping, propertyMapping.WithEmptyFallback("abc"));
FixedValueFallback fallback = Assert.IsType <FixedValueFallback>(propertyMapping.Pipeline.EmptyFallback);
Assert.Equal("abc", fallback.Value);
}