docs: public SplitDataProperties<T> splitsPartitionedBy(String partitionMethodId, String partitionFields) {
  
  		if (partitionFields == null) {
  			throw new InvalidProgramException("PartitionFields may not be null.");
  		}
  
  		String[] partitionKeysA = partitionFields.split(";");
  		if (partitionKeysA.length == 0) {
  			throw new InvalidProgramException("PartitionFields may not be empty.");
  		}
  
  		this.splitPartitionKeys = getAllFlatKeys(partitionKeysA);
  		if (partitionMethodId != null) {
  			this.splitPartitioner = new SourcePartitionerMarker<>(partitionMethodId);
  		}
  		else {
  			this.splitPartitioner = null;
  		}
  
  		return this;
  	}