default long remainingMillis() {
        long diff = elapsed();
        return diff > getTimeout() ? 0L : getTimeout() - diff;
    }
Gets the time in milliseconds until the cooldown will become inactive.

<p>If the cooldown is not active, this method returns <code>0</code>.</p>

@return the time in millis until the cooldown will expire
helper/src/main/java/me/lucko/helper/cooldown/Cooldown.java