public void putAll(Map<String, Object> context) {
   Hashtable<String, Object> ht = tlm.get();
   if (ht == null) {
     ht = new Hashtable<String, Object>(HT_SIZE);
     tlm.set(ht);
   }
   ht.putAll(context);
 }
 public void put(String key, Object o) {
   Hashtable<String, Object> ht = tlm.get();
   if (ht == null) {
     ht = new Hashtable<String, Object>(HT_SIZE);
     tlm.set(ht);
   }
   ht.put(key, o);
 }
 public void setContextMap(Map<String, Object> contextMap) {
   Hashtable<String, Object> ht = tlm.get();
   if (ht != null) {
     ht.clear();
   } else {
     ht = new Hashtable<String, Object>(HT_SIZE);
     tlm.set(ht);
   }
   ht.putAll(contextMap);
 }