integrity sha512-CiyeOxFT/JZyN5m0z9PfXw4SCBJ6Sygz1Dpl0wqjlhDEGGBP1GnsUVEL0p63hoG1fcj3fHynXi9NYO4nWOL+qQ==

path-exists@^4.0.0:
  version "4.0.0"
  resolved "https://registry.yarnpkg.com/path-exists/-/path-exists-4.0.0.tgz#513bdbe2d3b95d7762e8c1137efa195c6c61b5b3"
  integrity sha512-ak9Qy5Q7jYb2Wwcey5Fpvg2KoAc/ZIhLSLOSBmRmygPsGwkVVt0fZa0qrtMz+m6tJTAHfZQ8FnmB4MG4LWy7/w==

  // operator represents a key's relationship to a set of values.
  // Valid operators are In, NotIn, Exists and DoesNotExist.
  optional string operator = 2;

  // values is an array of string values. If the operator is In or NotIn,
  // the values array must be non-empty. If the operator is Exists or DoesNotExist,
  // the values array must be empty. This array is replaced during a strategic
  // merge patch.

// RoleBinding references a role, but does not contain it.  It can reference a Role in the same namespace or a ClusterRole in the global namespace.
// It adds who information via Subjects and namespace information by which namespace it exists in.  RoleBindings in a given
// namespace only have effect in that namespace.
// Deprecated in v1.17 in favor of rbac.authorization.k8s.io/v1 RoleBinding, and will no longer be served in v1.22.
message RoleBinding {

// RoleBinding references a role, but does not contain it.  It can reference a Role in the same namespace or a ClusterRole in the global namespace.
// It adds who information via Subjects and namespace information by which namespace it exists in.  RoleBindings in a given
// namespace only have effect in that namespace.
// Deprecated in v1.17 in favor of rbac.authorization.k8s.io/v1 RoleBinding, and will no longer be served in v1.22.
message RoleBinding {

// RoleBinding references a role, but does not contain it.  It can reference a Role in the same namespace or a ClusterRole in the global namespace.
// It adds who information via Subjects and namespace information by which namespace it exists in.  RoleBindings in a given
// namespace only have effect in that namespace.
message RoleBinding {
  // Standard object's metadata.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.ObjectMeta metadata = 1;

These types that have internal types are called "**generic**" types. And it's possible to declare them, even with their internal types.

To declare those types and the internal types, you can use the standard Python module `typing`. It exists specifically to support these type hints.

#### Newer versions of Python

The syntax using `typing` is **compatible** with all versions, from Python 3.6 to the latest ones, including Python 3.9, Python 3.10, etc.

</div>

This means that it will **always have a value**, it's just that sometimes the value could be `None` (or `null` in JSON).

That means that, clients using your API don't have to check if the value exists or not, they can **assume the field will always be there**, but just that in some cases it will have the default value of `None`.

  // If the key is empty, operator must be Exists; this combination means to match all values and all keys.
  // +optional
  optional string key = 1;

  // Operator represents a key's relationship to the value.
  // Valid operators are Exists and Equal. Defaults to Equal.
  // Exists is equivalent to wildcard for value, so that a pod can

If it doesn't see an `Authorization` header, or the value doesn't have a `Bearer ` token, it will respond with a 401 status code error (`UNAUTHORIZED`) directly.

You don't even have to check if the token exists to return an error. You can be sure that if your function is executed, it will have a `str` in that token.

You can try it already in the interactive docs:

<img src="/img/tutorial/security/image03.png">

- Make sure "Create separate module per source set" is selected
- Make sure  "Use default gradle wrapper" is selected
- Select a Java 11 VM as "Gradle JVM"
- In the "File already exists" dialogue, choose "Yes" to overwrite
- In the "Open Project" dialogue, choose "Delete Existing Project and Import"
- Revert the Git changes to files in the `.idea` folder