## Adding New Feature Constants

For consistency, features must be registered in [features.yaml](features.yaml), or your test will fail.  Each entry in this file will be equivalent to a dot delimited feature label.  For instance:

```yaml
    usability:

// to compute types and values, but in addition to Check, as these
// functions ignore the context in which an expression is used (e.g., an
// assignment). Thus, top-level untyped constants will return an
// untyped type rather than the respective context-specific type.
func CheckExpr(fset *token.FileSet, pkg *Package, pos token.Pos, expr ast.Expr, info *Info) (err error) {
	// determine scope
	var scope *Scope

	ext.RunQuietlyAndIgnore(constants.IPTables, iptV, nil, "-t", constants.NAT, "-D", constants.OUTPUT, "-p", constants.UDP, "-j", constants.ISTIOOUTPUT)
	ext.RunQuietlyAndIgnore(constants.IPTables, iptV, nil, "-t", constants.RAW, "-D", constants.OUTPUT, "-p", constants.UDP, "-j", constants.ISTIOOUTPUT)
	ext.RunQuietlyAndIgnore(constants.IPTables, ipt6V, nil, "-t", constants.NAT, "-D", constants.OUTPUT, "-p", constants.UDP, "-j", constants.ISTIOOUTPUT)

				ObjectMeta: metav1.ObjectMeta{
					Name: constants.NodeKubeletBootstrap,
				},
				RoleRef: rbac.RoleRef{
					APIGroup: rbac.GroupName,
					Kind:     "ClusterRole",
					Name:     constants.NodeBootstrapperClusterRoleName,
				},
				Subjects: []rbac.Subject{
					{
						Kind: rbac.GroupKind,
						Name: constants.NodeBootstrapTokenAuthGroup,
					},
				},
			}),
		},
		{

		ObjectMeta: metav1.ObjectMeta{
			Name: constants.NodeKubeletBootstrap,
		},
		RoleRef: rbac.RoleRef{
			APIGroup: rbac.GroupName,
			Kind:     "ClusterRole",
			Name:     constants.NodeBootstrapperClusterRoleName,
		},
		Subjects: []rbac.Subject{
			{
				Kind: rbac.GroupKind,
				Name: constants.NodeBootstrapTokenAuthGroup,
			},
		},
	})
}

	flag.BindEnv(fs, constants.InboundTProxyRouteTable, "r", "", &cfg.InboundTProxyRouteTable)

	flag.BindEnv(fs, constants.DryRun, "n", "Do not call any external dependencies like iptables.",
		&cfg.DryRun)

	flag.BindEnv(fs, constants.TraceLogging, "", "Insert tracing logs for each iptables rules, using the LOG chain.", &cfg.TraceLogging)

    %cst = arith.constant dense<0.000000e+00> : tensor<5xf32>
    %cst_0 = arith.constant dense<1.0> : tensor<5x384xf32>
    %cst_1 = arith.constant dense<1.0> : tensor<5x384xf32>

		EtcdAPICall:                      &metav1.Duration{Duration: constants.EtcdAPICallTimeout},
		TLSBootstrap:                     &metav1.Duration{Duration: constants.TLSBootstrapTimeout},
		Discovery:                        &metav1.Duration{Duration: constants.DiscoveryTimeout},
		UpgradeManifests:                 &metav1.Duration{Duration: constants.UpgradeManifestsTimeout},
	}
}

var (

	"istio.io/api/annotation"
	"istio.io/istio/pkg/config/constants"
)

var annotationPatch = []byte(fmt.Sprintf(
	`{"metadata":{"annotations":{"%s":"%s"}}}`,
	constants.AmbientRedirection,
	constants.AmbientRedirectionEnabled,
))

var annotationRemovePatch = []byte(fmt.Sprintf(
	`{"metadata":{"annotations":{"%s":null}}}`,
	constants.AmbientRedirection,
))

	channels := make([]wsstream.ChannelType, 5)
	channels[constants.StreamStdIn] = readChannel(opts.Stdin)
	channels[constants.StreamStdOut] = writeChannel(opts.Stdout)
	channels[constants.StreamStdErr] = writeChannel(opts.Stderr)
	channels[constants.StreamErr] = wsstream.WriteChannel
	channels[constants.StreamResize] = wsstream.ReadChannel
	return channels
}