Can hierarchyDims contain jointDims

[doom]

HI ALL:
I read the src code of kylin 2.2, and find:


In class CubeDes, if hierarchyDims contain jointDims will throw exception.
public void validateAggregationGroups() {
    ...
    if (CollectionUtils.containsAny(hierarchyDims, jointDims)) {
                logger.error("Aggregation group " + index + " hierarchy 
dimensions overlap with joint dimensions");
                throw new IllegalStateException(
                        "Aggregation group " + index + " hierarchy dimensions 
overlap with joint dimensions: "
                                + 
ensureOrder(CollectionUtils.intersection(hierarchyDims, jointDims)));
}


But in class AggregationGroup will replace the hierarchy dim with the joint 
dims witch contain it.
private void buildHierarchyMasks(RowKeyDesc rowKeyDesc) {
            .....
            for (int i = 0; i < hierarchy_dims.length; i++) {
                TblColRef hColumn = 
cubeDesc.getModel().findColumn(hierarchy_dims[i]);
                Integer index = rowKeyDesc.getColumnBitIndex(hColumn);
                long bit = 1L << index;


                // combine joint as logic dim
                if (dim2JointMap.get(bit) != null) {  
                    bit = dim2JointMap.get(bit);
                }


                mask.fullMask |= bit;
                allMaskList.add(mask.fullMask);
                dimList.add(bit);
            }

}


do i understand in a wrong way?