@Override
    public Map<K, V> generateFinalResult(final Map<K, V> object) {
        return doFinalReduction((Map<K, Object>) object, this.valueTraversal);
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/GroupStep.java