public static InputRDD createInputRDD(final Configuration hadoopConfiguration) {
        final InputRDD inputRDD;
        try {
            inputRDD = InputRDD.class.isAssignableFrom(hadoopConfiguration.getClass(Constants.GREMLIN_HADOOP_GRAPH_READER, Object.class)) ?
                hadoopConfiguration.getClass(Constants.GREMLIN_HADOOP_GRAPH_READER, InputRDD.class, InputRDD.class).newInstance() :
                InputFormatRDD.class.newInstance();
        } catch (final InstantiationException | IllegalAccessException e) {
            throw new IllegalStateException(e.getMessage(), e);
        }
        return inputRDD;
    }
Create an InputRDD instance based on {@value Constants#GREMLIN_HADOOP_GRAPH_READER} config
<p>
If {@value Constants#GREMLIN_HADOOP_GRAPH_READER} is of {@link InputRDD} format, instantiate an instance,
otherwise, instantiate an {@link InputFormatRDD} instance

@param hadoopConfiguration hadoop configurations
@return generated InputRDD instance
spark-gremlin/src/main/java/org/apache/tinkerpop/gremlin/spark/structure/io/SparkIOUtil.java