Vous pouvez également parrainer :

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

## FastAPIを強化するツールのスポンサーになる

ドキュメントで見たように、FastAPIはStarletteとPydanticという巨人の肩に乗っています。

以下のスポンサーになることもできます:

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

## 赞助 FastAPI 使用的工具

如您在本文档中所见，FastAPI 站在巨人的肩膀上，它们分别是 Starlette 和 Pydantic。

您还可以赞助：

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin （Pydantic）</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode （Starlette, Uvicorn）</a>

---

## FastAPI를 강화하는 도구의 스폰서가 되십시오

문서에서 보았듯이, FastAPI는 Starlette과 Pydantic 라는 거인의 어깨에 타고 있습니다.

다음의 스폰서가 될 수 있습니다

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

# Sub-dependencies { #sub-dependencies }

You can create dependencies that have **sub-dependencies**.

They can be as **deep** as you need them to be.

**FastAPI** will take care of solving them.

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

Then, we could use this `checker` in a `Depends(checker)`, instead of `Depends(FixedContentQueryChecker)`, because the dependency is the instance, `checker`, not the class itself.

And when solving the dependency, **FastAPI** will call this `checker` like:

```Python
checker(q="somequery")
```

import org.jspecify.annotations.Nullable;

/**
 * Abstract {@link Hasher} that handles converting primitives to bytes using a scratch {@code
 * ByteBuffer} and streams all bytes to a sink to compute the hash.
 *
 * @author Colin Decker
 */
abstract class AbstractByteHasher extends AbstractHasher {
  private @Nullable ByteBuffer scratch;

  /** Updates this hasher with the given byte. */
  protected abstract void update(byte b);

import java.util.Objects;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Closer}.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class CloserTest extends TestCase {

  private TestSuppressor suppressor;

  @Override
  protected void setUp() throws Exception {
    suppressor = new TestSuppressor();
  }

/**
 * A generator of {@code TestSuite} instances for testing {@code CharSource} implementations.
 * Generates tests of all methods on a {@code CharSource} given various inputs the source is
 * expected to contain.
 *
 * @author Colin Decker
 */
@AndroidIncompatible // TODO(b/230620681): Make this available (even though we won't run it).
@NullUnmarked
public class CharSourceTester extends SourceSinkTester<CharSource, String, CharSourceFactory> {

import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * Provides utility methods for working with character streams.
 *
 * @author Chris Nokleberg
 * @author Bin Zhu
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class CharStreams {

  // 2K chars (4K bytes)
  private static final int DEFAULT_BUF_SIZE = 0x800;