def has_param(key)
      code, message, value = @server.call("hasParam", @caller_id, key)
      case code
      when 1
        return value
      when -1
        raise message
      else
        return false
      end
    end
def has_param(key)
      code, message, value = @server.call("hasParam", @caller_id, key)
      case code
      when 1
        return value
      when -1
        raise message
      else
        return false
      end
    end
check if the master has the key
 @param [String] key key for check
 @return [String, Integer, Float, Boolean] value of key