{
  "settings": {
    "analysis": {
      "normalizer": {
        "self_normalizer": {
          "type": "custom",
          "char_filter": [],
          "filter": [
            "lowercase",
            "asciifolding"
          ]
        }
      }
    }
  },
  "mappings":{
    "properties":{
      "field_1":{
        "type":"keyword",
        "normalizer": "self_normalizer"
      }
    }
  }
}