public boolean isChanged() {
        return changed;
    }
Returns true if:
The config generation for the {@link ConfigSubscriber} that produced this is the first one in its life cycle. (Typically first time config.)
or
All configs for the subscriber have a new generation since the last time nextConfig() was called
AND it's the same generation AND there is a change in <strong>this</strong> handle's config.
(Typically calls for a reconfig.)

@return there is a new config
config/src/main/java/com/yahoo/config/subscription/ConfigHandle.java