test2

@Test
    public void testListBooksInHandsOf(){
        //given
        LibraryDatabase libraryDatabaseMock = mock(LibraryDatabase.class);
        BookLibrary bookLibrary = new BookLibrary(libraryDatabaseMock);
        LibraryUser libraryUser1 = new LibraryUser("Adam","Kowalski","123456789");
        LibraryUser libraryUser2 = new LibraryUser ("Kamil", "Kowalski", "123456789");
        LibraryUser libraryUser3 = new LibraryUser ("Anna","Nowak","123456789");
        List<Book> listOf0Books = new ArrayList<>();
        List<Book> listOf5Books = generateListOfNBooks(5);
        List<Book> listOf1Books = generateListOfNBooks(1);
        when(libraryDatabaseMock.listBooksInHandsOf(libraryUser1)).thenReturn(listOf1Books);
        when(libraryDatabaseMock.listBooksInHandsOf(libraryUser2)).thenReturn(listOf0Books);
        when(libraryDatabaseMock.listBooksInHandsOf(libraryUser3)).thenReturn(listOf5Books);
        //when
        List<Book> listOfBooks0 = bookLibrary.listBooksInHandsOf(libraryUser2);
        List<Book> listOfBooks5 = bookLibrary.listBooksInHandsOf(libraryUser3);
        List<Book> listOfBooks1 = bookLibrary.listBooksInHandsOf(libraryUser1);
        //then
        Assert.assertEquals(0,listOfBooks0.size());
        Assert.assertEquals(1,listOfBooks1.size());
        Assert.assertEquals(5,listOfBooks5.size());
    }