docs: public static BigDecimal deserializeBigDecimal(ByteBuffer buffer) {
          byte decimalBytes[] = new byte[16];
          buffer.get(decimalBytes);
          if (java.util.Arrays.equals(decimalBytes, NULL_INDICATOR)) {
              return null;
          }
          final BigDecimal bd = new BigDecimal(
                  new BigInteger(decimalBytes),
                          kDefaultScale, context);
          if (bd.precision() > 38) {
              throw new RuntimeException("Decimal " + bd + " has more than 38 digits of precision.");
          }
          return bd;
      }