"type": "LivechatSession",
"_id": "fasd6f5a4sd6f8a4sdf",
"topic": "topic of the session",
"createdAt": "2016-06-01T18:41:16.856Z",
"lastMessageAt": "2016-06-01T18:41:16.856Z",
"username": "visitor-username",
"department": "department",
"username": "agent.username",
"username": "visitor-username",
"msg": "message content",
"ts": "2016-06-01T18:41:16.856Z"
"username": "agent.username",
"agentId": "asdf89as6df8",
"msg": "message content from agent",
"ts": "2016-06-01T18:41:16.856Z"