@Test
public void testForOperation() {

    Server server = new Server("https://horizon-testnet.stellar.org");
    URI uri = server.effects()
            .forOperation(28798257847L)
            .cursor("85794837")
            .buildUri();
    assertEquals("https://horizon-testnet.stellar.org/operations/28798257847/effects?cursor=85794837", uri.toString());
}