@Test
public void shouldAddBook() throws Exception {

 when(bookService.create(any(Book.class))).thenReturn(new Book("123456789", "Test Book Stored", "T. Author"));
 mockMvc.perform(post("/books")
          .contentType(MediaType.APPLICATION_JSON)
          .content("{ \"isbn\" : \"123456789\"}, \"title\" : \"Test Book\", \"authors\" : [\"T. Author\"]"))
          .andExpect(status().isCreated())
          .andExpect(header().string("Location", "http://localhost/books/123456789"));
}