if (constants == null) {
        constants = populateCache(enumClass);
      }
      return constants;
    }
  }

  /**
   * Returns a serializable converter that converts between strings and {@code enum} values of type
   * {@code enumClass} using {@link Enum#valueOf(Class, String)} and {@link Enum#name()}. The
   * converter will throw an {@code IllegalArgumentException} if the argument is not the name of any

        }
    }

    @Nested
    @DisplayName("Hex Conversion Tests")
    class HexConversionTests {

        @Test
        @DisplayName("Various byte values are converted to uppercase hex")
        void testHexConversion() {
            byte[] challenge = new byte[] { (byte) 0x00, (byte) 0x0F, (byte) 0x10, (byte) 0x7F, (byte) 0x80, (byte) 0xFF };

And it will save the returned value in a <dfn title="A utility/system to store computed/generated values, to reuse them instead of computing them again.">"cache"</dfn> and pass it to all the "dependants" that need it in that specific request, instead of calling the dependency multiple times for the same request.

| Maximum number of versions per object                                           | 10000 (can be configured to higher values but we do not recommend beyond 10000) |

    /** Default number of rows to process in a single batch */
    protected int defaultRowSize = 100;

    /**
     * Default constructor for indexing helper.
     * Creates a new instance with default values.
     */
    public IndexingHelper() {
        // Default constructor
    }

    /** Interval between requests in milliseconds */
    protected long requestInterval = 500;

    /**

We can **update a hero**. For this we use an HTTP `PATCH` operation.

And in the code, we get a `dict` with all the data sent by the client, **only the data sent by the client**, excluding any values that would be there just for being the default values. To do it we use `exclude_unset=True`. This is the main trick. 🪄

Then we use `hero_db.sqlmodel_update(hero_data)` to update the `hero_db` with the data from `hero_data`.

Aber nun wissen Sie, dass Sie sie in **FastAPI** immer dann verwenden können, wenn Sie sie brauchen.

## Defaultwerte { #default-values }

Natürlich können Sie Defaultwerte verwenden, die nicht `None` sind.

Nehmen wir an, Sie möchten, dass der `q` Query-Parameter eine `min_length` von `3` hat und einen Defaultwert von „fixedquery“:

Defina um parâmetro de arquivo com um tipo de `UploadFile`:

{* ../../docs_src/request_files/tutorial001_an_py310.py hl[14] *}

Utilizar `UploadFile` tem várias vantagens sobre `bytes`:

* Você não precisa utilizar o `File()` no valor padrão do parâmetro.
* Ele utiliza um arquivo "spooled":
    * Um arquivo armazenado na memória até um limite máximo de tamanho, e após passar esse limite, ele será armazenado no disco.

import java.util.Random;
import org.jspecify.annotations.Nullable;
import sun.misc.Unsafe;

/**
 * A package-local class holding common representation and mechanics for classes supporting dynamic
 * striping on 64bit values. The class extends Number so that concrete subclasses must publicly do
 * so.
 */
@GwtIncompatible
@SuppressWarnings("SunApi") // b/345822163
abstract class Striped64 extends Number {
  /*

Boolean flag = BooleanConversionUtil.toBoolean("true");        // Returns true
Date date = DateConversionUtil.toDate("2023-12-25", "yyyy-MM-dd");

// Primitive conversions with default values
int primitiveInt = IntegerConversionUtil.toPrimitiveInt(value, "0");  // Default to 0 if null
```

### Collection Utilities with Java 21 Support
```java
import org.codelibs.core.collection.CollectionsUtil;