@Override
    public Object[] toArray() {
        List<Object> arr = new ArrayList<Object>(groupCollectors.size());
        for (GroupCollector<?,?> col : groupCollectors) {
            arr.add(col.get());
        }
        return arr.toArray();
    }
Default implementation of the Group interface

@author sasa
@author tiwe
querydsl-core/src/main/java/com/querydsl/core/group/GroupImpl.java