@Override
    protected Class<? extends InputFormat<NullWritable, VertexWritable>> getInputFormat() {
        return GraphSONInputFormat.class;
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
hadoop-gremlin/src/test/java/org/apache/tinkerpop/gremlin/hadoop/structure/io/graphson/GraphSONV3RecordReaderWriterTest.java