json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "type": "object",
      "title": "Wangscape tile groups schema",
      "description": "Lists Wangscape output tiles with locations, grouped by corner terrain types.",
      "patternProperties": {
          "^[0-9a-zA-Z_-]+\\.[0-9a-zA-Z_-]+\\.[0-9a-zA-Z_-]+\\.[0-9a-zA-Z_-]+$": {
              "type": "array",
              "title": "Tile group schema",
              "description": "Lists the locations of all output tiles with a given sequence of corner terrain types.",
              "items": {
                  "type": "object",
                  "title": "Tile location schema",
                  "description": "Specifies the location of a Wangscape output tile.",
                  "properties": {
                      "filename": {
                          "title": "Specifies the filename of the tileset containing the tile.",
                          "description": "",
                          "type": "string"
                      },
                      "x": {
                          "title": "Tile x offset schema",
                          "description": "Specifies the horizontal offset, in pixels, of the tile within the tileset.",
                          "type": "integer",
                          "minimum": 0
                      },
                      "y": {
                          "title": "Tile y offset schema",
                          "description": "Specifies the vertical offset, in pixels, of the tile within the tileset.",
                          "type": "integer",
                          "minimum": 0
                      }
                  },
                  "additionalProperties": false,
                  "required": [
                      "filename",
                      "x",
                      "y"
                  ]
              },
              "minItems": 1
          }
      }
  }