{
  "type": "object",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "properties": {
    "key1": {
      "type": "string"
    },
    "key2": {
      "type": "string"
    },
    "key3": {
      "type": "string"
    }
  },
  "required": [
    "key1",
    "key2"
  ]
}