@Override
  public Mono<GetCurrencyConversionsResponse> getCurrencyConversions(final GetCurrencyConversionsRequest request) {
    AuthenticationUtil.requireAuthenticatedDevice();

    final CurrencyConversionEntityList currencyConversionEntityList = currencyManager
        .getCurrencyConversions()
        .orElseThrow(Status.UNAVAILABLE::asRuntimeException);

    final List<GetCurrencyConversionsResponse.CurrencyConversionEntity> currencyConversionEntities = currencyConversionEntityList
        .getCurrencies()
        .stream()
        .map(cce -> GetCurrencyConversionsResponse.CurrencyConversionEntity.newBuilder()
            .setBase(cce.getBase())
            .putAllConversions(transformBigDecimalsToStrings(cce.getConversions()))
            .build())
        .toList();

    return Mono.just(GetCurrencyConversionsResponse.newBuilder()
        .addAllCurrencies(currencyConversionEntities).setTimestamp(currencyConversionEntityList.getTimestamp())
        .build());
  }
@Test
  void testGetCurrencyConversions() {
    final long timestamp = System.currentTimeMillis();
    when(currencyManager.getCurrencyConversions()).thenReturn(Optional.of(
        new CurrencyConversionEntityList(List.of(
            new CurrencyConversionEntity("FOO", Map.of(
                "USD", new BigDecimal("2.35"),
                "EUR", new BigDecimal("1.89")
            )),
            new CurrencyConversionEntity("BAR", Map.of(
                "USD", new BigDecimal("1.50"),
                "EUR", new BigDecimal("0.98")
            ))
        ), timestamp)));

    final GetCurrencyConversionsResponse currencyConversions = authenticatedServiceStub().getCurrencyConversions(
        GetCurrencyConversionsRequest.newBuilder().build());

    assertEquals(timestamp, currencyConversions.getTimestamp());
    assertEquals(2, currencyConversions.getCurrenciesCount());
    assertEquals("FOO", currencyConversions.getCurrencies(0).getBase());
    assertEquals("2.35", currencyConversions.getCurrencies(0).getConversionsMap().get("USD"));
  }