assertNotNull(content);
        assertTrue(content.length() > 0);
        assertTrue(content.contains("number_of_shards"));
    }

    @Test(expected = IOException.class)
    public void testLoadJsonResource_nonExistingResource() throws IOException {
        SettingsResourceLoader.loadJsonResource("non_existing_resource.json");
    }

    @Test
    public void testLoadJsonResourceWithSubstitution() throws IOException {