code: @SuppressWarnings("unchecked")
      @Override
      public <T> T execute() {
          Room sfsRoom = CommandUtil.getSfsRoom(room, extension);
          User sfsUser = null;
          if(username != null)
              sfsUser = sfsRoom.getUserByName(username);
          else
              sfsUser = sfsRoom.getUserById(userId);
          return (sfsUser != null) ? (T)sfsUser.getProperty(APIKey.USER) : null;
          
      }
docs: /* (non-Javadoc)
  @see com.tvd12.ezyfox.core.command.BaseCommand#execute()