Function booklibrs::actions::giveaway::simple::change_return_date_simple

pub fn change_return_date_simple(
    book_op: &Option<Weak<RefCell<Book>>>, 
    book_system: &mut BookSystem, 
    reader_base: &ReaderBase, 
    genres: &Genres, 
    caretaker: &mut Caretaker, 
    lang: Lang
) -> bool

Function that changes return date for already known book