mgw := MergeGateways(instances, &Proxy{}, nil)
	hosts := mgw.GetAutoPassthrughGatewaySNIHosts()
	expectedHosts := sets.Set[string]{}
	expectedHosts.InsertAll("a.apps.svc.cluster.local", "b.apps.svc.cluster.local")
	if !hosts.Equals(expectedHosts) {
		t.Errorf("expected to get: [a.apps.svc.cluster.local,b.apps.svc.cluster.local], got: %s", hosts.String())
	}
}

	testCases := []struct {
		hostPort     string
		expectedHost string
		expectedPort string
	}{
		{":54321", "", "54321"},
		{"server:54321", "server", "54321"},
		{":0", "", "0"},
		{"server:https", "server", "443"},
		{"server:http", "server", "80"},
	}

	for _, testCase := range testCases {
		host, port := mustSplitHostPort(testCase.hostPort)
		if testCase.expectedHost != host {

// and checks that the resulting equals the expectedCost if expectedCost is non-zero, and that the resulting cost is >= expectedCostExceedsLimit
// if expectedCostExceedsLimit is non-zero. Typically, only expectedCost or expectedCostExceedsLimit is non-zero, not both.
func schemaChecker(schema *schema.Structural, expectedCost uint64, expectedCostExceedsLimit uint64, t *testing.T) func(t *testing.T) {

					for _, err := range errs {
						t.Errorf("unexpected error: %v", err)
					}

					if tt.expectedCost != 0 {
						if remainingBudget != tt.costBudget-tt.expectedCost {
							t.Errorf("expected cost to be %d, but got %d", tt.expectedCost, tt.costBudget-remainingBudget)
						}
						return
					}
					if tt.expectSkipped {