*/
public DataSetMerger(DataSet targetDataSet, DataSet sourceDataSet) throws IllegalArgumentException {
CheckParameterUtil.ensureParameterNotNull(targetDataSet, "targetDataSet");
this.targetDataSet = targetDataSet;
this.sourceDataSet = sourceDataSet;
conflicts = new ConflictCollection();
mergedMap = new HashMap<>();
objectsWithChildrenToMerge = new HashSet<>();
objectsToDelete = new HashSet<>();
}