ERXFetchSpecificationBatchIterator iterator = new ERXFetchSpecificationBatchIterator(fs);
iterator.setEditingContext(ec);
while (iterator.hasNextBatch()) {
NSArray objects = iterator.nextBatch();
if (iterator.currentBatchIndex() % treshhold == 0) {
ec.unlock();
// ec.dispose();
ec = ERXEC.newEditingContext();
ec.lock();
iterator.setEditingContext(ec);
}