### Question:
B2AccountAuthorizationCache { synchronized String getAccountId() throws B2Exception{ if (accountId == null) { get(); } return accountId; } B2AccountAuthorizationCache(B2StorageClientWebifier webifier,
                                B2AccountAuthorizer accountAuthorizer);   }### Answer:
@Test public void testGetAccountIdCallsGet() throws B2Exception { final B2AccountAuthorization auth1 = makeAuthWithAccountId(accountId, 1); doReturn(auth1).when(authorizer).authorize(webifier); assertTrue(cache.getAccountId().equals(accountId)); verify(authorizer, times(1)).authorize(webifier); assertTrue(cache.getAccountId().equals(accountId)); verify(authorizer, times(1)).authorize(webifier); }