public static Seconds ofHours(int hours) {
        if (hours == 0) {
            return ZERO;
        }
        return new Seconds(Math.multiplyExact(hours, SECONDS_PER_HOUR));
    }
public static Seconds ofHours ( int hours ) { if ( hours == 0 ) { return ZERO ; } return new Seconds ( Math . multiplyExact ( hours , SECONDS_PER_HOUR ) ) ; }
Obtains a {@code Seconds} representing the number of seconds
equivalent to a number of hours.
<p>
The resulting amount will be second-based, with the number of seconds
equal to the number of hours multiplied by 3600.

@param hours  the number of hours, positive or negative
@return the amount with the input hours converted to seconds, not null
@throws ArithmeticException if numeric overflow occurs