Remove implements CombinationResult { @Override public boolean hasChanges() { return true; } Remove(Debt... debtsToBeRemoved); @Override boolean hasChanges(); @Override void applyTo(Collection<Debt> existingDebts); @Override boolean equals(Object o); @Override int hashCode(); @Override String toString();  }
@Test public void shouldHaveChanges() throws Exception { assertThat(new Remove(), hasChanges(equalTo(true))); }