    @Test
    public void testFunction() {

        JsonObject args = new JsonObject();
        JsonObject response = FunctionApp.main(args);
        assertNotNull(response);
        String greetings = response.getAsJsonPrimitive("greetings").getAsString();
        assertNotNull(greetings);
        assertEquals("Hello! Welcome to OpenWhisk on OpenShift", greetings);
    }