Метод проверки доступности

// Request to check availability for a Slot.
message CheckAvailabilityRequest {
  // The appointment slot that is being checked (required)
  Slot slot = 1;
}

// Response for the CheckAvailability RPC with the availability of the
// appointment slot.
message CheckAvailabilityResponse {
  // The requested slot. (required)
  Slot slot = 1;

  // Number of available spots.
  // 0 indicates that the appointment slot is not available. (required)
  int32 count_available = 2;

  // If set, the last time (in seconds since the Unix epoch) that this specific
  // appointment slot can be cancelled through Reserve with Google. This field
  // will override any service-level cancellation rules. (optional)
  //
  // Deprecated: Use scheduling_rule_overrides.last_online_cancellable_sec
  // in the Availability feed instead.
  int64 last_online_cancellable_sec = 5 [deprecated = true];

  // This enum indicates what requirements exist for the user to acknowledge or
  // view the requested slots duration/end time.
  enum DurationRequirement {
    // The handling of the end time is not specified. This is the default.
    DURATION_REQUIREMENT_UNSPECIFIED = 0;

    // The end time is not shown to the user.
    DO_NOT_SHOW_DURATION = 1;

    // The end time has to be shown to the user before an appointment can be
    // made.
    MUST_SHOW_DURATION = 2;
  }

  // The requirement to show the slots duration and/or endtime. This field will
  // be ignored if the slot is unavailable. (optional)
  //
  // Deprecated: Use duration_requirement in the Availability feed instead.
  DurationRequirement duration_requirement = 3 [deprecated = true];

  // Optionally, the partner can return additional updated information about the
  // availability for this merchant if this information is present when
  // responding to the CheckAvailabilityRequest and if there is no negative
  // impact on the CheckAvailability request latency.
  // For instance an entire day of merchant availability for a superset of
  // resources can be returned here.
  AvailabilityUpdate availability_update = 4;
}

// An update to one ore more slots indicating that the availability for the
// associated time has potentially changed.
message AvailabilityUpdate {
  repeated SlotAvailability slot_availability = 1;
}

// An inventory slot and associated count of open spots.
message SlotAvailability {
  Slot slot = 1;

  // Number of available spots.
  // 0 indicates that the appointment slot is not available. (required)
  int32 count_available = 2;
}