{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/TopSource",
  "title": "TopSource",
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "description": "Initial referring domain."
    },
    "visitors": {
      "type": "integer",
      "description": "Unique visitors from this source."
    },
    "change": {
      "allOf": [
        {
          "$ref": "#/components/schemas/WoWChange"
        }
      ],
      "nullable": true,
      "description": "Period-over-period change in visitors, null when not meaningful."
    }
  },
  "required": [
    "change",
    "name",
    "visitors"
  ]
}