Filmbesprechungen, filmpädagogische Begleitmaterialien, News, Termine, Veranstaltungen, Adressen und Links für die schulische und außerschulische Filmarbeit.
There are some valid arguments against using Optional as a method parameter type, but they are not good enough to say that you should avoid it at all costs
K. Järvelin, and J. Kekäläinen. Proceedings of the 23rd Annual International ACM SIGIR Conference on Research and Development in Information Retrieval (SIGIR 2000), page 41--48. New York, NY, USA, ACM, (2000)
D. Swallow, M. Blythe, and P. Wright. EACE '05: Proceedings of the 2005 annual conference on European association of cognitive ergonomics, (September 2005)