protected List<Worker> makeWorkersImpl(boolean verbose) throws IOException {
TransactionSelector transSel = new TransactionSelector(
twitterConf.getTracefile(),
twitterConf.getTracefile2(),
workConf.getTransTypes());
List<TwitterOperation> trace = Collections.unmodifiableList(transSel.readAll());
transSel.close();
ArrayList<Worker> workers = new ArrayList<Worker>();
for (int i = 0; i < workConf.getTerminals(); ++i) {
TransactionGenerator<TwitterOperation> generator =
new TraceTransactionGenerator(trace);