code: public Iterator<T> getSplit(int num, int numPartitions) {
  		if (numPartitions < 1 || num < 0 || num >= numPartitions) {
  			throw new IllegalArgumentException();
  		}
  
  		return split(numPartitions)[num];
  	}
docs: Splits this iterator into <i>n</i> partitions and returns the <i>i-th</i> partition
  out of those.
  
  @param num The partition to return (<i>i</i>).
  @param numPartitions The number of partitions to split into (<i>n</i>).
  @return The iterator for the partition.