custom writablecomparable with complex fields

[Adeel Qureshi]

I want to write a custom writablecomparable object with two List objects
within it ..

public class CompositeKey implements WritableComparable {

private List<JsonKey> groupBy;
private List<JsonKey> sortBy;
...
}

what I am not sure about is how to write

readFields and write methods for this object. Any help would be appreciated.

Thanks
Adeel