code: function Session_onRequest(channel, message) {
    if (message.to == "server") {
      return onRequestServer(this, channel, message)
    }
  
    var agent = this.getAgentByID(message.to)
  
    if (!agent) {
      channel.sendMessage({
        type:  "response",
        name:  message.name,
        from:  message.to,
        id:    message.id,
        error: "agent not found"
      })
      return
    }
  
    var reqID = message.to + ":" + message.id
  
    this.reqCBs.set(reqID, channel)
    agent.channel.sendMessage(message)
  }
docs: ------------------------------------------------------------------------------