code: public boolean containsCommand(String commandId) {
          
          Assert.notNull(commandId, "commandId");
          
          if (this.commandMap.containsKey(commandId)) {
              return true;
          }
          
          if (this.parent != null) {
              return this.parent.containsCommand(commandId);
          }
          
          return false;
          
      }
docs: {@inheritDoc}