when(manager.getLibraries()).thenReturn(libraries);
MockSlingHttpServletRequest request = new MockSlingHttpServletRequest(
"/apps/acs-commons/components/utilities/designer/clientlibsmanager/options", "js", "json", null,
null);
MockSlingHttpServletResponse response = new MockSlingHttpServletResponse();
servlet.doGet(request, response);
assertEquals("application/json", response.getContentType());
JSONArray array = new JSONArray(response.getOutput().toString());
assertEquals(4, array.length());
}