docs: public Period multipliedBy(int scalar) {
          if (this == ZERO || scalar == 1) {
              return this;
          }
          int[] values = getValues();  // cloned
          for (int i = 0; i < values.length; i++) {
              values[i] = FieldUtils.safeMultiply(values[i], scalar);
          }
          return new Period(values, getPeriodType());
      }