code: public boolean deleteWatcher(String name, Watcher watcher){
          if(LOGGER.isTraceEnabled()){
              LOGGER.trace("Delete a watcher, name={}", name);
          }
          synchronized(watchers){
  
              if (watchers.containsKey(name)) {
                  return watchers.get(name).remove(watcher);
              }
          }
          return false;
      }
docs: Delete a watcher from the Service.
  
  @param name
  the Service Name.
  @param watcher
  the Watcher object.
  @return
  true if success.