@Override
    public List<T> get(final String key, final Object value) {
        final Map<Object, Set<T>> keyMap = this.index.get(key);
        if (null == keyMap) {
            return Collections.emptyList();
        } else {
            Set<T> set = keyMap.get(indexable(value));
            if (null == set)
                return Collections.emptyList();
            else
                return new ArrayList<>(set);
        }
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
tinkergraph-gremlin/src/main/java/org/apache/tinkerpop/gremlin/tinkergraph/structure/TinkerIndex.java