### Question:
LeaseRenewer { String getClientName(final String id) { return "DFSClient_" + id + "_" + clienNamePostfix; } private  LeaseRenewer(Factory.Key factorykey); @Override String toString();  }### Answer:
@Test public void testClientName() throws IOException { String clientName = renewer.getClientName("NONMAPREDUCE"); Assert.assertTrue("bad client name: " + clientName, clientName.startsWith("DFSClient_NONMAPREDUCE_")); }