code: public static long raiseToPower(int value, int power)
      {
          if (power < 0)
          {
              throw new IllegalArgumentException("This method does not support negative powers.");
          }
          long result = 1;
          for (int i = 0; i < power; i++)
          {
              result *= value;
          }
          return result;
      }
docs: Calculate the first argument raised to the power of the second.
  This method only supports non-negative powers.
  @param value The number to be raised.
  @param power The exponent (must be positive).
  @return {@code value} raised to {@code power}.