public PartitionOperator<T> partitionByHash(int... fields) {
		return new PartitionOperator<>(this, PartitionMethod.HASH, new Keys.ExpressionKeys<>(fields, getType()), Utils.getCallLocationName());
	}
public PartitionOperator < T > partitionByHash ( int ... fields ) { return new PartitionOperator < > ( this , PartitionMethod . HASH , new Keys . ExpressionKeys < > ( fields , getType ( ) ) , Utils . getCallLocationName ( ) ) ; }
Hash-partitions a DataSet on the specified key fields.

<p><b>Important:</b>This operation shuffles the whole DataSet over the network and can take significant amount of time.

@param fields The field indexes on which the DataSet is hash-partitioned.
@return The partitioned DataSet.