protected void setUp() throws Exception {
JobConf conf = new JobConf();
conf.set(JTConfig.JT_IPC_ADDRESS, "localhost:0");
conf.set(JTConfig.JT_HTTP_ADDRESS, "0.0.0.0:0");
conf.setLong(JTConfig.JT_TRACKER_EXPIRY_INTERVAL, 1000);
clock = new FakeClock();
// We use a "partial mock" of JobTracker which lets us see when certain
// methods are called. If we were writing JobTracker from scratch then
// we would make it call another object which we would mock out instead
// (and use a real JobTracker) so we could perform assertions on the mock.
// See http://mockito.googlecode.com/svn/branches/1.8.0/javadoc/org/mockito/Mockito.html#16