code: @Override
      public final void ready() throws CoreException {
  
          synchronized (this) {
  
              this.subCommandList = defineSubCommand();
  
              if (this.subCommandList == null || this.subCommandList.isEmpty()) {
                  throw new CoreRuntimeException("Warning, 'defineSubCommand' should return at least one Command Key.");
              }
  
              for (final UniqueKey<? extends Command> commandKey : this.subCommandList) {
                  localFacade().retrieve(commandKey);
              }
  
          }
  
          initCommand();
      }
docs: {@inheritDoc}