* `tags: List[str] = []` has a default of an empty list: `[]`.

but you might want to omit them from the result if they were not actually stored.

For example, if you have models with many optional attributes in a NoSQL database, but you don't want to send very long JSON responses full of default values.

### Use the `response_model_exclude_unset` parameter { #use-the-response-model-exclude-unset-parameter }

	// 10,000
	PartNumber int

	// Entity tag returned when the part was uploaded.
	ETag string

	Size int64

	// Checksum values. Optional.
	ChecksumCRC32     string
	ChecksumCRC32C    string
	ChecksumSHA1      string
	ChecksumSHA256    string
	ChecksumCRC64NVME string
}

```console
$ cd docs/en/
```

Then run `mkdocs` in that directory:

```console
$ mkdocs serve --dev-addr 127.0.0.1:8008
```

///

#### Typer CLI (optional)

The instructions here show you how to use the script at `./scripts/docs.py` with the `python` program directly.

	nameAddr := p.address(operands[0])
	if !p.validSymbol("TEXT", &nameAddr, false) {
		return
	}
	name := symbolName(&nameAddr)
	next := 1

	// Next operand is the optional text flag, a literal integer.
	var flag = int64(0)
	if len(operands) == 3 {
		flag = p.evalInteger("TEXT", operands[1])
		next++
	}

	// Issue an error if we see a function defined as ABIInternal

/// tip | Tipp

Die Dokumentationsoberfläche interagiert mit dem von Ihnen ausgewählten Server.

///

/// note | Technische Details

Die Eigenschaft `servers` in der OpenAPI-Spezifikation ist optional.

The `HeroUpdate` *data model* is somewhat special, it has **all the same fields** that would be needed to create a new hero, but all the fields are **optional** (they all have a default value). This way, when you update a hero, you can send just the fields that you want to update.

Das `HeroUpdate`-*Datenmodell* ist etwas Besonderes, es hat **die selben Felder**, die benötigt werden, um einen neuen Helden zu erstellen, aber alle Felder sind **optional** (sie haben alle einen Defaultwert). Auf diese Weise, wenn Sie einen Helden aktualisieren, können Sie nur die Felder senden, die Sie aktualisieren möchten.

/// tip

The docs UI will interact with the server that you select.

///

/// note | Technical Details

The `servers` property in the OpenAPI specification is optional.

## Pydantic `Settings` { #pydantic-settings }

Felizmente, o Pydantic fornece uma ótima utilidade para lidar com essas configurações vindas de variáveis de ambiente com <a href="https://docs.pydantic.dev/latest/concepts/pydantic_settings/" class="external-link" target="_blank">Pydantic: Settings management</a>.

    public void refresh(K key) {
      throw new UnsupportedOperationException();
    }
  }

  /**
   * LinkedHashMap that enforces it's maximum size and logs events in a StatsCounter object and an
   * optional RemovalListener.
   *
   * @param <K> the base key type
   * @param <V> the base value type
   */
  private class CapacityEnforcingLinkedHashMap<K, V> extends LinkedHashMap<K, Timestamped<V>> {