code: public final void setNumberOfDigits(final int numberOfDigits) {
          Condition.INSTANCE
                  .ensureAtLeast(numberOfDigits, 1, "The number of digits must be at least 1");
          this.numberOfDigits = numberOfDigits;
          setNumber(Math.min(getNumber(), getMaxNumber(numberOfDigits)));
      }
docs: Sets the number of digits of the numbers, the preference should allow to choose.
  
  @param numberOfDigits
  The number of digits, which should be set, as an {@link Integer} value. The number of
  digits must be at least 1