assertThat(ArbitraryInstances.get(Appendable.class).toString()).isEmpty();
    assertThat(ArbitraryInstances.get(StringBuilder.class).toString()).isEmpty();
    assertThat(ArbitraryInstances.get(StringBuffer.class).toString()).isEmpty();
    assertFreshInstanceReturned(
        ArrayList.class,
        HashMap.class,
        Appendable.class,
        StringBuilder.class,
        StringBuffer.class,

  @AndroidIncompatible // problem with equality of Type objects?
  public void testFreshInstance() {
    assertFreshInstances(
        String.class,
        CharSequence.class,
        Appendable.class,
        StringBuffer.class,
        StringBuilder.class,
        Pattern.class,
        MatchResult.class,
        Number.class,
        int.class,
        Integer.class,
        long.class,

  @AndroidIncompatible // problem with equality of Type objects?
  public void testFreshInstance() {
    assertFreshInstances(
        String.class,
        CharSequence.class,
        Appendable.class,
        StringBuffer.class,
        StringBuilder.class,
        Pattern.class,
        MatchResult.class,
        Number.class,
        int.class,
        Integer.class,
        long.class,

    checkArgument(
        implementations.put(type, implementation) == null,
        "Implementation for %s was already registered",
        type);
  }

  static {
    setImplementation(Appendable.class, StringBuilder.class);
    setImplementation(BlockingQueue.class, LinkedBlockingDeque.class);
    setImplementation(BlockingDeque.class, LinkedBlockingDeque.class);

Diese können so **tief** verschachtelt sein, wie nötig.

**FastAPI** kümmert sich darum, sie aufzulösen.

## Erste Abhängigkeit, „Dependable“ { #first-dependency-dependable }

Sie könnten eine erste Abhängigkeit („Dependable“) wie folgt erstellen:

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

	if err != nil {
		t.Fatal(err)
	}

	err = fs.AppendFile(context.Background(), "voldir", "/file", []byte("hello"))
	if err != nil {
		t.Fatal(err)
	}

	// Try to create a file that includes a file in its path components.
	// In *nix, this returns syscall.ENOTDIR while in windows we receive the following error.
	err = fs.AppendFile(context.Background(), "voldir", "/file/obj1", []byte("hello"))

이것을 해결하는 일은 **FastAPI**가 알아서 처리합니다.

## 첫 번째 의존성 "dependable" { #first-dependency-dependable }

다음과 같이 첫 번째 의존성("dependable")을 만들 수 있습니다:

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

이 의존성은 선택적 쿼리 파라미터 `q`를 `str`로 선언하고, 그대로 반환합니다.

매우 단순한 예시(그다지 유용하진 않음)이지만, 하위 의존성이 어떻게 동작하는지에 집중하는 데 도움이 됩니다.

## 두 번째 의존성 "dependable"과 "dependant" { #second-dependency-dependable-and-dependant }

它們可以按你的需要，層級任意加深。

**FastAPI** 會負責解析它們。

## 第一個相依項 "dependable" { #first-dependency-dependable }

你可以建立第一個相依項（"dependable"）如下：

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

它宣告了一個可選的查詢參數 `q`（型別為 `str`），然後直接回傳它。

這很簡單（不太實用），但有助於我們專注於子相依如何運作。

## 第二個相依，同時是 "dependable" 也是 "dependant" { #second-dependency-dependable-and-dependant }

接著你可以建立另一個相依函式（"dependable"），同時它也宣告了自己的相依（因此它同時也是 "dependant"）：

## Друга залежність, «dependable» і «dependant» { #second-dependency-dependable-and-dependant }

Далі ви можете створити іншу функцію залежності («dependable»), яка водночас оголошує власну залежність (тож вона також є «dependant»):

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Зосередьмося на оголошених параметрах:

Puedes crear dependencias que tengan **sub-dependencias**.

Pueden ser tan **profundas** como necesites.

**FastAPI** se encargará de resolverlas.

## Primera dependencia "dependable" { #first-dependency-dependable }

Podrías crear una primera dependencia ("dependable") así:

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

Declara un parámetro de query opcional `q` como un `str`, y luego simplemente lo devuelve.