code: @Test public void testLotsOfPutsAndGets(){
    SessionIdGenerator generator=new SecureRandomSessionIdGenerator();
    final Map<String,String> reference=new HashMap<String,String>();
    final SecureHashMap<String,String> map=new SecureHashMap<String,String>();
    for (int i=0; i < 10000; ++i) {
      String key=generator.createSessionId();
      String value=generator.createSessionId();
      map.put(key,value);
      reference.put(key,value);
    }
    for (  Map.Entry<String,String> entry : reference.entrySet()) {
      Assert.assertEquals(entry.getValue(),map.get(entry.getKey()));
      Assert.assertEquals(entry.getValue(),map.remove(entry.getKey()));
    }
    Assert.assertEquals(0,map.size());
  }
  