def search_param(key)
      code, message, value = @server.call("searchParam", @caller_id, key)
      case code
      when 1
        return value
      when -1
        raise message
      else
        return false
      end
    end
def search_param(key)
      code, message, value = @server.call("searchParam", @caller_id, key)
      case code
      when 1
        return value
      when -1
        raise message
      else
        return false
      end
    end
search the all namespace for key
 @param [String] key key for search
 @return [Array] values