public JaccardIndex<K, VV, EV> setGroupSize(int groupSize) {
		Preconditions.checkArgument(groupSize > 0, "Group size must be greater than zero");

		this.groupSize = groupSize;

		return this;
	}
public JaccardIndex < K , VV , EV > setGroupSize ( int groupSize ) { Preconditions . checkArgument ( groupSize > 0 , "Group size must be greater than zero" ) ; this . groupSize = groupSize ; return this ; }
Override the default group size for the quadratic expansion of neighbor
pairs. Small groups generate more data whereas large groups distribute
computation less evenly among tasks.

<p>The default value should be near-optimal for all use cases.

@param groupSize the group size for the quadratic expansion of neighbor pairs
@return this