@Test
public void getUserTest() {

    Response response = target().path("users/" + UsernameTestFilter.USERNAME).request().get();
    assertEquals(response.getStatus(), 200);
    verify(engineManager).retrieveUser(UsernameTestFilter.USERNAME);
    JSONObject result = JSONObject.fromObject(response.readEntity(String.class));
    assertFalse(result.containsKey("@graph"));
    assertTrue(result.containsKey("@id"));
    assertEquals(result.getString("@id"), user.getResource().stringValue());
}