书接上文，多个关联模型这种情况很常见。

特别是用户模型，因为：

* **输入模型**应该含密码
* **输出模型**不应含密码
* **数据库模型**需要加密的密码

/// danger | "危险"

千万不要存储用户的明文密码。始终存储可以进行验证的**安全哈希值**。

如果不了解这方面的知识，请参阅[安全性中的章节](security/simple-oauth2.md#password-hashing){.internal-link target=_blank}，了解什么是**密码哈希**。

///

## 多个模型

下面的代码展示了不同模型处理密码字段的方式，及使用位置的大致思路：

//// tab | Python 3.10+

```Python hl_lines="7  9  14  20  22  27-28  31-33  38-39"

import org.opensearch.search.aggregations.bucket.filter.FilterAggregationBuilder;
import org.opensearch.search.aggregations.bucket.global.GlobalAggregationBuilder;
import org.opensearch.search.aggregations.bucket.missing.MissingAggregationBuilder;
import org.opensearch.search.aggregations.bucket.range.IpRangeAggregationBuilder;
import org.opensearch.search.aggregations.bucket.sampler.SamplerAggregationBuilder;

  @Override
  public Hasher newHasher() {
    return new SipHasher(c, d, k0, k1);
  }

  // TODO(kak): Implement and benchmark the hashFoo() shortcuts.

  @Override
  public String toString() {
    return "Hashing.sipHash" + c + "" + d + "(" + k0 + ", " + k1 + ")";
  }

  @Override
  public boolean equals(@CheckForNull Object object) {
    if (object instanceof SipHashFunction) {

			return nil, err
		}
	}

	json := jsoniter.ConfigCompatibleWithStandardLibrary
	if err := json.Unmarshal(data, &srvCfg); err != nil {
		return nil, err
	}

	// Add any missing entries
	return srvCfg.Merge(), nil
}

// ConfigSys - config system.
type ConfigSys struct{}

// Init - initializes config system from config.json.
func (sys *ConfigSys) Init(objAPI ObjectLayer) error {

	if !ok {
		return sealedKey, errMissingInternalSealAlgorithm
	}
	b64SealedKey, ok := metadata[MetaSealedKeySSEC]
	if !ok {
		return sealedKey, Errorf("The object metadata is missing the internal sealed key for SSE-C")
	}

	// Check whether all extracted values are well-formed
	iv, err := base64.StdEncoding.DecodeString(b64IV)
	if err != nil || len(iv) != 32 {

Mas com todos os benefícios:

* Suporte do editor (compleção em todo canto!)
* Conversão de dados (leia-se parsing/serialização)
* Validação de dados
* Documentação dos esquemas

	if b[0] == '{' && b[len(b)-1] == '}' { // JSON object
		var c ciphertext
		if err := c.UnmarshalJSON(b); err != nil {
			// It may happen that a random ciphertext starts with '{' and ends with '}'.
			// In such a case, parsing will fail but we must not return an error. Instead
			// we return the ciphertext as it is.
			return b, kms.AES256
		}

		b = b[:0]
		b = append(b, c.Bytes...)
		b = append(b, c.IV...)

                return false;
            }
        }

        if ( !foundPreauth ) {
            log.error("Missing preauth negotiate context");
            return false;
        }
        if ( !foundEnc && ( caps & Smb2Constants.SMB2_GLOBAL_CAP_ENCRYPTION ) != 0 ) {
            log.error("Missing encryption negotiate context");
            return false;
        }
        else if ( !foundEnc ) {

 * that [get] was called. Updates and removals after the call do not impact ongoing reads.
 *
 * This class is tolerant of some I/O errors. If files are missing from the filesystem, the
 * corresponding entries will be dropped from the cache. If an error occurs while writing a cache
 * value, the edit will fail silently. Callers should handle other problems by catching

  val random: Random,
  private val perMessageDeflate: Boolean,
  private val noContextTakeover: Boolean,
  private val minimumDeflateSize: Long,
) : Closeable {
  /** This holds outbound data for compression and masking. */
  private val messageBuffer = Buffer()

  /** The [Buffer] of [sink]. Write to this and then flush/emit [sink]. */
  private val sinkBuffer: Buffer = sink.buffer
  private var writerClosed = false