{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "allOf": [
    { "$ref": "../base-cf.schema.json#/defs/baseSpecification" },
    {
      "properties": {
        "implementation": {
          "const": "SourceSpecification"
        },
        "fields": {
          "type": "object",
          "properties": {
            "value": {
              "type": "integer",
              "enum": [1, 2, 3, 4, 5, 6, 7, 8, 9]
            }
          },
          "required": ["value"],
          "additionalProperties": false
        }
      },
      "required": ["implementation", "fields"]
    }
  ]
}