সার্ভিসক্লাস স্পেসিফিকেশন

প্রোটো সংজ্ঞা 

// Attributes characterizing the amenities and ride comfort of a journey on a
// vehicle.
message ServiceClass {
  // A high level enum describing the service class type.
  enum ServiceClassType {
    // Global service classes
    FIRST_CLASS = 1;
    SECOND_CLASS = 2;

    // Only a single service class is offered by the operator. The service class
    // may not even have a name because there is no distinction to be made.
    SINGLE_CLASS = 3;
    BUSINESS_CLASS = 4;

    // Additional global or per-market service classes can be added.  Please
    // reach out to the Google Transport team if additional service classes are
    // needed for your use case.

    // Japan specific train ticket classes
    NON_RESERVED_SECOND_CLASS = 201;
    RESERVED_SECOND_CLASS = 202;
    RESERVED_GREEN_CAR_CLASS = 203;
    RESERVED_GRAN_CLASS = 204;
    // Brazil specific service classes.
    CONVENCIONAL = 205;
    EXECUTIVO = 206;
    SEMILEITO = 207;
    LEITO = 208;
    CAMA = 209;
  }

  ServiceClassType type = 1;
}

JSON নমুনা 

{
  "type": "FIRST_CLASS"
}