You might notice that to create an instance of a Python class, you use that same syntax.

For example:

```Python
class Cat:
    def __init__(self, name: str):
        self.name = name


fluffy = Cat(name="Mr Fluffy")
```

In this case, `fluffy` is an instance of the class `Cat`.

And to create `fluffy`, you are "calling" `Cat`.

So, a Python class is also a **callable**.

		}
		ref.ForeignKey = f
	}

	for name, rel := range relation.JoinTable.Relationships.Relations {
		if _, ok := joinSchema.Relationships.Relations[name]; !ok {
			rel.Schema = joinSchema
			joinSchema.Relationships.Relations[name] = rel
		}
	}
	relation.JoinTable = joinSchema

	return nil
}

// Use use plugin
func (db *DB) Use(plugin Plugin) error {
	name := plugin.Name()

func RISCV64SpecialOperand(name string) riscv.SpecialOperand {
	if riscv64SpecialOperand == nil {
		// Generate mapping when function is first called.
		riscv64SpecialOperand = map[string]riscv.SpecialOperand{}
		for opd := riscv.SPOP_BEGIN; opd < riscv.SPOP_END; opd++ {
			riscv64SpecialOperand[opd.String()] = opd
		}
	}
	if opd, ok := riscv64SpecialOperand[name]; ok {
		return opd
	}
	return riscv.SPOP_END
}

    private final boolean ignoreCase;

    public StopTokenPrefixFilterFactory(final IndexSettings indexSettings, final Environment environment, final String name,
            final Settings settings) {
        super(indexSettings, name, settings);

        final List<String> wordList = Analysis.parseWordList(environment, settings, "stopwords", s -> s);
        if (wordList != null) {

                final String name = searchFieldLog.getFirst();
                if (contentFieldNameSet.contains(name)) {
                    if (sb.length() > 0) {
                        sb.append(TEXT_SEP);
                    }
                    sb.append(searchFieldLog.getSecond());
                    fields.add(name);
                } else if (tagFieldNameSet.contains(name)) {

        return asJson(new ApiResult.ApiPluginResponse().plugins(list).status(ApiResult.Status.OK).result());
    }

    /**
     * Installs a plugin with the specified name and version.
     *
     * @param body the plugin installation data containing name and version
     * @return JSON response indicating success or failure
     */
    // POST /api/admin/plugin
    @Execute

     */
    private String ntlmDomain;

    /**
     * Return proxy server host name.
     *
     * @return proxy server host name
     */
    public String getHost() {
        return host;
    }

    /**
     * Set proxy host name.
     *
     * @param host proxy server host name
     */
    public void setHost(String host) {
        this.host = host;
    }

    /**

	<modelVersion>4.0.0</modelVersion>
	<artifactId>fess-crawler-opensearch</artifactId>
	<packaging>jar</packaging>
	<name>Fess Crawler OpenSearch</name>
	<parent>
		<groupId>org.codelibs.fess</groupId>
		<artifactId>fess-crawler-parent</artifactId>
		<version>15.3.0-SNAPSHOT</version>
		<relativePath>../pom.xml</relativePath>
	</parent>
	<build>

In diesem Fall erwartet **FastAPI** einen Body wie:

```JSON hl_lines="2"
{
    "item": {
        "name": "Foo",
        "description": "The pretender",
        "price": 42.0,
        "tax": 3.2
    }
}
```

statt:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2
}
```

## Zusammenfassung

In this case **FastAPI** will expect a body like:

```JSON hl_lines="2"
{
    "item": {
        "name": "Foo",
        "description": "The pretender",
        "price": 42.0,
        "tax": 3.2
    }
}
```

instead of:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2
}
```

## Recap { #recap }