json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "definitions": {
          "numberWithUnit": {
              "properties": {
                  "unit": {
                      "type": "string"
                  },
                  "value": {
                      "type": "number"
                  }
              },
              "required": [
                  "value",
                  "unit"
              ],
              "type": "object"
          }
      },
      "id": "http://schema.envirocar.org/fueling.create.json#",
      "properties": {
          "car": {
              "type": "string"
          },
          "comment": {
              "type": "string"
          },
          "cost": {
              "$ref": "#/definitions/numberWithUnit"
          },
          "fuelType": {
              "type": "string"
          },
          "mileage": {
              "$ref": "#/definitions/numberWithUnit"
          },
          "missedFuelStop": {
              "type": "boolean"
          },
          "time": {
              "_format": "date-time",
              "type": "string"
          },
          "volume": {
              "$ref": "#/definitions/numberWithUnit"
          }
      },
      "required": [
          "fuelType",
          "car",
          "cost",
          "mileage",
          "volume",
          "time"
      ],
      "type": "object"
  }