Fix ReferenceTest so that it works properly even under Java7
Fix ReferenceTest so that it works properly even under Java7

tomdkt/kryo,kidaa/kryo,irudyak/kryo,xfrendx/kryo,hierynomus/kryo,mikee805/kryo,EsotericSoftware/kryo,magro/kryo,narahari92/kryo,doubleyoung/kryo,narahari92/kryo,EsotericSoftware/kryo,EsotericSoftware/kryo,childRon/kryo,EsotericSoftware/kryo,childRon/kryo,hierynomus/kryo,romix/kryo,mikee805/kryo,doubleyoung/kryo,tomdkt/kryo,kidaa/kryo,xfrendx/kryo,irudyak/kryo,hepin1989/kryo,hepin1989/kryo,magro/kryo