if (dsc instanceof MergeDSCollection) {
throw new MergeDataException(DataInfo.getId(dsc) + " is already a merge of collection");
}
// Same time reference for all created synchronous time stamped data
TimeSource timeReference = null;
AsynchronousMergeDataSource mds = null;
for (int i = 0; i < dsc.size(); i++) {
try {
DataSource data = (DataSource) dsc.get(i);
String id = DataInfo.getId(data);