docs: public static Number power(Number self, Number exponent) {
          double base, exp, answer;
          base = self.doubleValue();
          exp = exponent.doubleValue();
  
          answer = Math.pow(base, exp);
          if ((double) ((int) answer) == answer) {
              return (int) answer;
          } else if ((double) ((long) answer) == answer) {
              return (long) answer;
          } else {
              return answer;
          }
      }