enable elasticsearch code example

Example: "enabled": false in elasticsearch mapping

PUT my-index-000001
{
  "mappings": {
    "properties": {
      "user_id": {
        "type":  "keyword"
      },
      "last_updated": {
        "type": "date"
      },
      "session_data": { 
        "type": "object",
        "enabled": false
      }
    }
  }
}

PUT my-index-000001/_doc/session_1
{
  "user_id": "kimchy",
  "session_data": { 
    "arbitrary_object": {
      "some_array": [ "foo", "bar", { "baz": 2 } ]
    }
  },
  "last_updated": "2015-12-06T18:20:22"
}

PUT my-index-000001/_doc/session_2
{
  "user_id": "jpountz",
  "session_data": "none", 
  "last_updated": "2015-12-06T18:22:13"
}