{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

이렇게 하면 `checker.fixed_content` 속성에 `"bar"`라는 값을 담아 의존성을 "매개변수화"할 수 있습니다.

## 인스턴스를 의존성으로 사용하기

그런 다음, `Depends(FixedContentQueryChecker)` 대신 `Depends(checker)`에서 이 `checker` 인스턴스를 사용할 수 있으며,
클래스 자체가 아닌 인스턴스 `checker`가 의존성이 됩니다.

의존성을 해결할 때 **FastAPI**는 이 `checker`를 다음과 같이 호출합니다:

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

		b, _ := io.ReadAll(r)
		return string(b)
	}
	checkEq := func(a, b string) {
		if a != b {
			t.Fatalf("Unexpected equality failure")
		}
	}

	checkEq(readAll(NewDummyDataGen(0, 0)), "")

	checkEq(readAll(NewDummyDataGen(10, 0)), readAll(NewDummyDataGen(10, int64(len(alphabets)))))

	checkEq(readAll(NewDummyDataGen(100, 0)), readAll(NewDummyDataGen(50, 0))+readAll(NewDummyDataGen(50, 50)))

使用以下代码创建类实例：

{* ../../docs_src/dependencies/tutorial011.py hl[16] *}

这样就可以**参数化**依赖项，它包含 `checker.fixed_content` 的属性 - `"bar"`。

## 把实例作为依赖项

然后，不要再在 `Depends(checker)` 中使用 `Depends(FixedContentQueryChecker)`， 而是要使用 `checker`，因为依赖项是类实例 - `checker`，不是类。

处理依赖项时，**FastAPI** 以如下方式调用 `checker`：

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

……并用*路径操作函数*的参数 `fixed_content_included` 返回依赖项的值：

    }

    /**
     * Dispatches all listeners {@linkplain #enqueue enqueued} prior to this call, serially and in
     * order.
     */
    @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
    void dispatch() {
      boolean scheduleEventRunner = false;
      synchronized (this) {
        if (!isThreadScheduled) {
          isThreadScheduled = true;
          scheduleEventRunner = true;

          <item index="10" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
          <item index="11" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
          <item index="12" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />

   * fact the static type of {@link Throwable} is occasionally justified even for a method with no
   * {@code throws} clause: Some such methods can in fact throw a checked exception (e.g., by
   * calling code written in Kotlin).) Typically, we want to let a {@link Throwable} from such a
   * method propagate untouched, just as we'd typically let it do for a non-reflective call.

  }

  @Override
  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  public void addListener(Runnable listener, Executor executor) {
    checkNotNull(listener, "Runnable was null.");
    checkNotNull(executor, "Executor was null.");
    try {
      executor.execute(listener);
    } catch (Exception e) { // sneaky checked exception

   * fact the static type of {@link Throwable} is occasionally justified even for a method with no
   * {@code throws} clause: Some such methods can in fact throw a checked exception (e.g., by
   * calling code written in Kotlin).) Typically, we want to let a {@link Throwable} from such a
   * method propagate untouched, just as we'd typically let it do for a non-reflective call.

     * This method is not supported in the Fess implementation.
     *
     * @param checker the credential checker to use
     * @throws UnsupportedOperationException always thrown as this method is not supported
     */
    @Override
    protected void checkCredential(final TypicalLoginAssist<String, FessUserBean, FessUser>.CredentialChecker checker) {

	if idxName != "idx_public_table_name" {
		t.Errorf("invalid index name generated, got %v", idxName)
	}

	chkName := ns.CheckerName("public.table", "name")
	if chkName != "chk_public_table_name" {
		t.Errorf("invalid checker name generated, got %v", chkName)
	}

	joinTable := ns.JoinTableName("user_languages")
	if joinTable != "public.user_languages" {
		t.Errorf("invalid join table generated, got %v", joinTable)
	}