当消息发送方发送一条文本信息时，消息接收方会监听到两条信息发送

async _handleMessageReceived(event) {
	console.log(event)
    if (!this._targetUserId) {
      return
    }

    const currentConversationMessage = event.data.filter(item => {
      return item.from === this._targetUserId
    })

    if (currentConversationMessage.length) {
      this.messageList = this.messageList.concat(currentConversationMessage);
      await Tim.getInstance().setMessageRead(this._targetUserId)
    }
  },

第1条正确的信息console打印

event.data.payload: {
	text:'文本消息'
}

第二条有问题的空白消息console

event.data.payload: {
	data:'{"businessID":"user_typing_status","typingStatus":1,"version":1,"userAction":0,"actionParam":"EIMAMSG_InputStatus_End"}',
	description: ""
	extension: ""	
}

想知道那条空白信息是怎么来的