@NullSource is an ArgumentsSource which provides a single
null argument to the annotated @ParameterizedClass or
@ParameterizedTest.
Note that @NullSource cannot be used for an argument that has
a primitive type, unless the argument is converted to a corresponding wrapper
type with an org..
This annotation is inherited to subclasses.
org.junit.jupiter.params.provider.ArgumentsSource , org.junit.jupiter.params.ParameterizedClass , org.junit.jupiter.params.ParameterizedTest , EmptySource, NullAndEmptySource