@Test
public void createsProxyObjectForInterface() {

    IBook book = JsonUtils.createProxy(IBook.class);
    assertNotNull(book);
    assertEquals(null, book.getAuthor());
    assertEquals(null, book.getTitle());
    assertEquals(0, book.getPages());
    assertEquals(0.0, book.getPrice(), 0.01);
    assertEquals(0L, book.getIsdn());
    assertEquals(false, book.getAvailability());
    assertEquals(false, book.getDelivery());
    book.setAuthor("Vincent Massol");
    book.setTitle("JUnit in Action");
    book.setPages(386);
    book.setPrice(19.37);
    book.setIsdn(93011099534534L);
    book.setAvailability(true);
    book.setDelivery(false);
    assertEquals("Vincent Massol", book.getAuthor());
    assertEquals("JUnit in Action", book.getTitle());
    assertEquals(386, book.getPages());
    assertEquals(19.37, book.getPrice(), 0.01);
    assertEquals(93011099534534L, book.getIsdn());
    assertEquals(true, book.getAvailability());
    assertEquals(false, book.getDelivery());
    assertNotNull(book.toString());
}