### Question:
PaymentFlowServices implements Jsonable { @NonNull public Set<String> getAllSupportedDataKeys() { return supportedDataKeys; } PaymentFlowServices(Collection<PaymentFlowServiceInfo> paymentFlowServiceInfoList); int getNumberOfFlowServices(); @NonNull List<PaymentFlowServiceInfo> getAll(); @NonNull Observable<PaymentFlowServiceInfo> stream(); @Nullable PaymentFlowServiceInfo getFlowServiceFromId(String id); boolean isCustomRequestTypeSupported(String requestType); @NonNull Set<String> getAllCustomRequestTypes(); boolean isCurrencySupported(String currency); @NonNull Set<String> getAllSupportedCurrencies(); @NonNull Set<String> getAllSupportedPaymentMethods(); boolean isDataKeySupported(String dataKey); @NonNull Set<String> getAllSupportedDataKeys(); @Override String toJson(); static PaymentFlowServices fromJson(String json);  }### Answer:
@Test public void shouldCollateDataKeysCorrectly() throws Exception { Set<String> allSupportedDataKeys = paymentFlowServices.getAllSupportedDataKeys(); assertThat(allSupportedDataKeys).hasSize(3); assertThat(allSupportedDataKeys).containsOnly("dataOne", "dataTwo", "dataThree"); }