@Nonnull
    static Cooldown of(long amount, @Nonnull TimeUnit unit) {
        return new CooldownImpl(amount, unit);
    }
Creates a cooldown lasting a specified amount of time

@param amount the amount of time
@param unit the unit of time
@return a new cooldown
helper/src/main/java/me/lucko/helper/cooldown/Cooldown.java