@Test
public void getProxyTicket_ValidService_ProxyTicketValue() {

    String service = "http://httpbin.org/get";
    Assertion assertion = mock(Assertion.class);
    AttributePrincipal attributePrincipal = mock(AttributePrincipal.class);
    when(assertionProvider.getAssertion()).thenReturn(assertion);
    when(assertion.getPrincipal()).thenReturn(attributePrincipal);
    when(attributePrincipal.getProxyTicketFor(service)).thenReturn("ST-21-c1gk6jBcfYnatLbNExfx-0623277bc36a");
    assertThat(proxyTicketProvider.getProxyTicket(service)).isEqualTo("ST-21-c1gk6jBcfYnatLbNExfx-0623277bc36a");
    verify(assertionProvider, times(1)).getAssertion();
    verify(assertion, times(1)).getPrincipal();
    verify(attributePrincipal, times(1)).getProxyTicketFor(service);
}