public SparkGraphComputer persistContext(final boolean persist) {
        return configure(GREMLIN_SPARK_PERSIST_CONTEXT, persist);
    }
Determines if the Spark context should be left open preventing Spark from garbage collecting unreferenced RDDs.
spark-gremlin/src/main/java/org/apache/tinkerpop/gremlin/spark/process/computer/SparkGraphComputer.java