```JSON
{
  "detail": [
    {
      "type": "missing",
      "loc": [
        "query",
        "needy"
      ],
      "msg": "Field required",
      "input": null,
      "url": "https://errors.pydantic.dev/2.1/v/missing"
    }
  ]
}
```

`needy` zorunlu bir parametre olduğundan dolayı bağlantıda tanımlanması gerekir:

```

	// maximum sleep duration between objects to slow down heal operation.
	Sleep   time.Duration `json:"sleep"`
	IOCount int           `json:"iocount"`

	DriveWorkers int `json:"drive_workers"`

	// Cached value from Bitrot field
	cache struct {
		// -1: bitrot enabled, 0: bitrot disabled, > 0: bitrot cycle
		bitrotCycle time.Duration
	}
}

// BitrotScanCycle returns the configured cycle for the scanner healing
// -1 for not enabled
//

			if err != nil {
				return nil, fmt.Errorf("column %v not found", name)
			}
			// The position count starts at 1.
			idx--
			if idx >= len(r.csvRecord) || idx < 0 {
				// If field index > number of columns, return null
				return sql.FromNull(), nil
			}
			return sql.FromBytes([]byte(r.csvRecord[idx])), nil
		}
		// TODO: Return Missing?
		return nil, fmt.Errorf("column %v not found", name)
	}

}

// MetricSpec specifies how to scale based on a single metric
// (only `type` and one other matching field should be set at once).
message MetricSpec {
  // type is the type of metric source.  It should be one of "ContainerResource", "External",
  // "Object", "Pods" or "Resource", each mapping to a matching field in the object.
  // Note: "ContainerResource" type is available on when the feature-gate
  // HPAContainerMetrics is enabled

}

// MetricSpec specifies how to scale based on a single metric
// (only `type` and one other matching field should be set at once).
message MetricSpec {
  // type is the type of metric source.  It should be one of "ContainerResource",
  // "External", "Object", "Pods" or "Resource", each mapping to a matching field in the object.
  // Note: "ContainerResource" type is available on when the feature-gate
  // HPAContainerMetrics is enabled

            addFieldToSource(sourceMap, "x121Address", x121Address);
        }
        return sourceMap;
    }

    protected void addFieldToSource(Map<String, Object> sourceMap, String field, Object value) {
        sourceMap.put(field, value);
    }

    // ===================================================================================
    //                                                                      Basic Override

   * constructor calls (as does readObject()).
   */
  @SuppressWarnings("nullness:initialization.field.uninitialized") // For J2KT (see above)
  private transient @Nullable BiEntry<K, V>[] hashTableKToV;

  @SuppressWarnings("nullness:initialization.field.uninitialized") // For J2KT (see above)
  private transient @Nullable BiEntry<K, V>[] hashTableVToK;

				if !rl.Expiration.IsNull() || !rl.NoncurrentVersionExpiration.IsNull() {
					expiryRuleRemoved = true
					break
				}
			}
		}

		// Form empty ILM details with `ExpiryUpdatedAt` field and save
		var cfgData []byte
		if expiryRuleRemoved {
			var lcCfg lifecycle.Lifecycle
			currtime := time.Now()
			lcCfg.ExpiryUpdatedAt = &currtime
			cfgData, err = xml.Marshal(lcCfg)
			if err != nil {

```{ .python .annotate hl_lines="1  5  8-11  14-17  23-25  28" }
{!../../docs_src/dataclasses/tutorial003.py!}
```

1. Wir importieren `field` weiterhin von Standard-`dataclasses`.

2. `pydantic.dataclasses` ist ein direkter Ersatz für `dataclasses`.

3. Die Datenklasse `Author` enthält eine Liste von `Item`-Datenklassen.

In that case, you can simply swap the standard `dataclasses` with `pydantic.dataclasses`, which is a drop-in replacement:

{* ../../docs_src/dataclasses/tutorial003.py hl[1,5,8:11,14:17,23:25,28] *}

1. We still import `field` from standard `dataclasses`.

2. `pydantic.dataclasses` is a drop-in replacement for `dataclasses`.

3. The `Author` dataclass includes a list of `Item` dataclasses.