docs: private static MonetaryAmountsSingletonSpi monetaryAmountsSingletonSpi() {
          try {
              return Bootstrap.getService(MonetaryAmountsSingletonSpi.class);
          } catch (Exception e) {
              Logger.getLogger(Monetary.class.getName())
                      .log(Level.SEVERE, "Failed to load MonetaryAmountsSingletonSpi.", e);
              return null;
          }
      }