@Test
public void createGroupTest() {

    // Setup:
    when(engineManager.groupExists(anyString())).thenReturn(false);
    FormDataMultiPart fd = new FormDataMultiPart();
    fd.field("title", "newGroup");
    fd.field("description", "This is a description");
    fd.field("members", "John Doe");
    fd.field("members", "Jane Doe");
    fd.field("roles", "admin");
    Response response = target().path("groups")
            .request().post(Entity.entity(fd, MediaType.MULTIPART_FORM_DATA));
    assertEquals(response.getStatus(), 201);
    verify(engineManager).storeGroup(eq(ENGINE_NAME), any(Group.class));
}