DefaultConstraints: []v1.TopologySpreadConstraint{
					{
						MaxSkew:           1,
						TopologyKey:       "node",
						WhenUnsatisfiable: v1.DoNotSchedule,
					},
					{
						MaxSkew:           2,
						TopologyKey:       "node",
						WhenUnsatisfiable: v1.DoNotSchedule,
					},
				},
				DefaultingType: config.ListDefaulting,
			},
			wantErrs: field.ErrorList{
				&field.Error{

					{
						TopologyKey:       "planet",
						WhenUnsatisfiable: v1.DoNotSchedule,
						MaxSkew:           2,
					},
				},
			},
			want: &configv1.PodTopologySpreadArgs{
				DefaultConstraints: []v1.TopologySpreadConstraint{
					{
						TopologyKey:       "planet",
						WhenUnsatisfiable: v1.DoNotSchedule,
						MaxSkew:           2,
					},
				},

			{
				WhenUnsatisfiable: api.DoNotSchedule,
				TopologyKey:       "kubernetes.io/hostname",
				MaxSkew:           1,
			},
		}
		defaultConstraints = []api.TopologySpreadConstraint{
			{
				NodeAffinityPolicy: &honor,
				NodeTaintsPolicy:   &ignore,
				WhenUnsatisfiable:  api.DoNotSchedule,
				TopologyKey:        "kubernetes.io/hostname",

			testPods: []*v1.Pod{
				st.MakePod().Name("p").UID("p").Label("foo", "").Priority(highPriority).
					SpreadConstraint(1, "zone", v1.DoNotSchedule, st.MakeLabelSelector().Exists("foo").Obj(), nil, nil, nil, nil).
					SpreadConstraint(1, "hostname", v1.DoNotSchedule, st.MakeLabelSelector().Exists("foo").Obj(), nil, nil, nil, nil).
					Obj(),
			},
			initPods: []*v1.Pod{

			TopologyKey:       "k8s.io/zone",
			WhenUnsatisfiable: core.DoNotSchedule,
			MinDomains:        utilpointer.Int32(3),
		}},
		wantFieldErrors: field.ErrorList{},
	}, {
		name: "missing MaxSkew",
		constraints: []core.TopologySpreadConstraint{
			{TopologyKey: "k8s.io/zone", WhenUnsatisfiable: core.DoNotSchedule},
		},

// unsatisfiable constraint.
type UnsatisfiableConstraintAction string

const (
	// DoNotSchedule instructs the scheduler not to schedule the pod
	// when constraints are not satisfied.
	DoNotSchedule UnsatisfiableConstraintAction = "DoNotSchedule"
	// ScheduleAnyway instructs the scheduler to schedule the pod
	// even if constraints are not satisfied.

				),
				tf.RegisterBindPlugin(defaultbinder.Name, defaultbinder.New),
			},
			nodes: []string{"node1", "node2"},
			pod: st.MakePod().Name("p").UID("p").Label("foo", "").SpreadConstraint(1, "hostname", v1.DoNotSchedule, &metav1.LabelSelector{
				MatchExpressions: []metav1.LabelSelectorRequirement{
					{
						Key:      "foo",
						Operator: metav1.LabelSelectorOpExists,
					},
				},

}

// +enum
type UnsatisfiableConstraintAction string

const (
	// DoNotSchedule instructs the scheduler not to schedule the pod
	// when constraints are not satisfied.
	DoNotSchedule UnsatisfiableConstraintAction = "DoNotSchedule"
	// ScheduleAnyway instructs the scheduler to schedule the pod
	// even if constraints are not satisfied.

message TopologySpreadConstraint {
  // MaxSkew describes the degree to which pods may be unevenly distributed.
  // When `whenUnsatisfiable=DoNotSchedule`, it is the maximum permitted difference
  // between the number of matching pods in the target topology and the global minimum.
  // The global minimum is the minimum number of matching pods in an eligible domain

	}
	// When MinDomains is non-nil, whenUnsatisfiable must be DoNotSchedule.
	if action != core.DoNotSchedule {
		allErrs = append(allErrs, field.Invalid(fldPath, minDomains, fmt.Sprintf("can only use minDomains if whenUnsatisfiable=%s, not %s", core.DoNotSchedule, action)))
	}
	return allErrs
}

// ValidateTopologyKey tests that the argument is a valid TopologyKey.