optional string operation = 2;

  // APIVersion defines the version of this resource that this field set
  // applies to. The format is "group/version" just like the top-level
  // APIVersion field. It is necessary to track the version of a field
  // set because it cannot be automatically converted.
  optional string apiVersion = 3;

  // Time is the timestamp of when the ManagedFields entry was added. The