<groupId>org.codelibs</groupId>
	<artifactId>corelib</artifactId>
	<packaging>jar</packaging>
	<name>CodeLibs Core Library</name>
	<version>0.7.2-SNAPSHOT</version>
	<description>Core library providing essential utilities and functionalities.</description>
	<url>https://github.com/codelibs/corelib</url>
	<inceptionYear>2012</inceptionYear>
	<licenses>
		<license>
			<name>The Apache Software License, Version 2.0</name>

    <version>4.1.0-SNAPSHOT</version>
  </parent>

  <artifactId>maven-settings-builder</artifactId>

  <name>Maven Settings Builder (deprecated)</name>
  <description>The effective settings builder, with inheritance and password decryption.</description>

  <contributors>
    <contributor>
      <name>Thomas Meyer</name>
    </contributor>
  </contributors>

  <dependencies>
    <dependency>

from typing import Annotated

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


class User(BaseModel):
    username: str
    full_name: str | None = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Item,

    }

    private
    fun findVersionFromJavadoc(javadoc: Javadoc): String? =
        javadoc.blockTags
            .find { tag -> tag.tagName == "since" }
            ?.content?.elements?.find { description -> description is JavadocSnippet }
            ?.toText()

    private
    fun nodeName(it: Node?, unit: CompilationUnit, file: File) = when (it) {

与声明查询参数一样，包含默认值的模型属性是可选的，否则就是必选的。把默认值设为 `None` 可使其变为可选。

例如，上述模型声明如下 JSON "object"（即 Python `dict`）：

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...由于 `description` 和 `tax` 是可选的（默认值为 `None`），下面的 JSON "object" 也有效：

```JSON
{
    "name": "Foo",
    "price": 45.2
}
```

## 声明为参数 { #declare-it-as-a-parameter }

Por ejemplo, el modelo anterior declara un “`object`” JSON (o `dict` en Python) como:

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...dado que `description` y `tax` son opcionales (con un valor por defecto de `None`), este “`object`” JSON también sería válido:

```JSON
{
    "name": "Foo",
    "price": 45.2
}

    <version>4.1.0-SNAPSHOT</version>
  </parent>

  <artifactId>maven-api-metadata</artifactId>

  <name>Maven 4 API :: Repository Metadata</name>
  <description>Maven 4 API - Immutable Repository Metadata model.</description>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-annotations</artifactId>
    </dependency>
  </dependencies>

  <version>11-SNAPSHOT</version>
  <name>Model inheritance test parent: module directory != artifactId</name>
  <description>
    artifactId == "child-artifact-id"
    but expect path on SCM and site == "child"
    feature: support "project.directory" property, ressembling future model addition of "directory" element along "artifactId"
  </description>

  <!-- 5 inherited urls with ${project.directory} added to parent instead of artifactId -->

	<modelVersion>4.0.0</modelVersion>
	<artifactId>fess-crawler-lasta</artifactId>
	<packaging>jar</packaging>
	<name>Fess Crawler for LastaFlute</name>
	<description>This is LastaFlute support.</description>
	<parent>
		<groupId>org.codelibs.fess</groupId>
		<artifactId>fess-crawler-parent</artifactId>
		<version>15.6.0-SNAPSHOT</version>
		<relativePath>../pom.xml</relativePath>
	</parent>
	<build>

        assertEquals("maven-jar-plugin", pd.getArtifactId());
        assertEquals("2.3-SNAPSHOT", pd.getVersion());
        assertEquals("jar", pd.getGoalPrefix());
        assertEquals("plugin-description", pd.getDescription());
        assertFalse(pd.isIsolatedRealm(), "Expected " + pd + ".isIsolatedRealm() to return false");
        assertTrue(pd.isInheritedByDefault(), "Expected " + pd + ".isInheritedByDefault() to return true");