// If WhenUnsatisfiable is set to DoNotSchedule, incoming pod can only be scheduled
  // to zone2(zone3) to become 3/2/1(3/1/2) as ActualSkew(2-1) on zone2(zone3) satisfies
  // MaxSkew(1). In other words, the cluster can still be imbalanced, but scheduler
  // won't make it *more* imbalanced.
  // It's a required field.
  optional string whenUnsatisfiable = 3;

  // LabelSelector is used to find matching pods.