protected double doTransactions(EntityManager pm, int numObjects) {
// Perform a series of transactions that will trigger
// adds, deletes, and udpates
Duration timeToAMD = new Duration(
"Adds, removes, and dletes for " + numObjects + " objects.");
timeToAMD.start();
// create objects
RuntimeTest1[] persistables = new RuntimeTest1[numObjects];
for (int i = 0; i < persistables.length; i++) {
persistables[i] = new RuntimeTest1("foo #" + i, i);