// +optional
  optional EventSource source = 5;

  // The time at which the event was first recorded. (Time of server receipt is in TypeMeta.)
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time firstTimestamp = 6;

  // The time at which the most recent occurrence of this event was recorded.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastTimestamp = 7;