@Test
public void testForTransaction() {

    Server server = new Server("https://horizon-testnet.stellar.org");
    URI uri = server.operations()
            .forTransaction("991534d902063b7715cd74207bef4e7bd7aa2f108f62d3eba837ce6023b2d4f3")
            .buildUri();
    assertEquals("https://horizon-testnet.stellar.org/transactions/991534d902063b7715cd74207bef4e7bd7aa2f108f62d3eba837ce6023b2d4f3/operations", uri.toString());
}