### Question:
FederatedRepositoryImpl implements FederatedRepository { @Override public FederatedDataSet getTrainingData() { return dataSource.getTrainingData(); } FederatedRepositoryImpl(FederatedDataSource dataSource, FederatedNetworkDataSource networkDataSource); @Override FederatedDataSet getTrainingData(); @Override FederatedDataSet getTestData(); @Override FederatedDataSet getCrossValidationData(); @Override Observable<Boolean> uploadGradient(byte[] gradient); @Override Observable<byte[]> retrieveGradient(); @Override Observable<Integer> registerModel();  }### Answer:
@Test public void testGetTrainingData() { given(dataSource.getTrainingData()).willReturn(dataSet); FederatedDataSet trainingData = cut.getTrainingData(); assertNotNull(trainingData); }