code: public static BigDecimal inverse(final BigDecimal value) {
          if (isNotZero(value)) {
              return BigDecimal.ONE.setScale(MAX_SCALE_FOR_INVERSE).divide(value, BigDecimal.ROUND_HALF_UP);
          }
          return null;
      }
docs: Return the inverse of value if no tnull of zero
  @param value the nullable BigDecimal
  @return 1 / value (if not null of zero)