@Override
    public Set<Class> getImplementations() {
        return IMPLEMENTATION;
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
spark-gremlin/src/test/java/org/apache/tinkerpop/gremlin/spark/process/computer/SparkHadoopGraphProvider.java