for (int i = 0; i < rdds.length; i++) {
if (parents.get(i) instanceof PTableBase) {
rdds[i] = (JavaPairRDD) ((SparkCollection) parents.get(i)).getJavaRDDLike(runtime);
} else {
JavaRDD rdd = (JavaRDD) ((SparkCollection) parents.get(i)).getJavaRDDLike(runtime);
rdds[i] = rdd.mapPartitions(new PairFlatMapDoFn(IdentityFn.getInstance(), runtime.getRuntimeContext()));
}
}
return runtime.getSparkContext().union(rdds);
}
}