```

## Recap

You can declare additional validations and metadata for your parameters.

Generic validations and metadata:

* `alias`
* `title`
* `description`
* `deprecated`

Validations specific for strings:

* `min_length`
* `max_length`
* `pattern`

In these examples you saw how to declare validations for `str` values.

```Python
item: Item
```

...and with that single declaration you get:

* Editor support, including:
    * Completion.
    * Type checks.
* Validation of data:
    * Automatic and clear errors when the data is invalid.
    * Validation even for deeply nested JSON objects.

        internalReporter.create {
            id(
                "configuration-cache-" + DeprecationMessageBuilder.createDefaultDeprecationId(message),
                message,
                GradleCoreProblemGroup.validation()
            )
            contextualLabel(message)
            documentOfProblem(problem)
            locationOfProblem(problem)
            severity(severity.toProblemSeverity())

# disable_pgv: disables protoc-gen-validation. This is not used buts adds many MB to Envoy protos
# not set vtprotobuf: this adds some performance improvement, but at a binary cost increase that is not worth it for the agent
AGENT_TAGS=agent,disable_pgv
# disable_pgv: disables protoc-gen-validation. This is not used buts adds many MB to Envoy protos

        override fun file(path: Any): File {
            onAccess("file")
            return delegate.file(path)
        }

        override fun file(path: Any, validation: PathValidation): File {
            onAccess("file")
            return delegate.file(path, validation)
        }

        override fun uri(path: Any): URI {
            onAccess("uri")
            return delegate.uri(path)
        }

It doesn't mean "`one_person` is the **class** called `Person`".

## Pydantic models

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> is a Python library to perform data validation.

You declare the "shape" of the data as classes with attributes.

And each attribute has a type.

        }

        if (javaVersion.isCompatibleWith(JavaVersion.VERSION_22)) {
            // Does not work due to JVM validation issue: https://youtrack.jetbrains.com/issue/KT-66919
            excludeTestsMatching "org.gradle.docs.samples.*.building-kotlin-*"
            // Incompatible for unknown reasons, investigation ongoing

 *    - `readLine()`, `readFully(ByteArray)`, `readFully(ByteArray, Int, Int)`, `readUnshared()`, `readFields()`, `transferTo(OutputStream)` and `readAllBytes()`.
 * - validations registered via [ObjectInputStream.registerValidation] are simply ignored;
 * - the `readObjectNoData` method, if present, is never invoked;
 */
class JavaObjectSerializationCodec(