## Используем экземпляр как зависимость { #use-the-instance-as-a-dependency }

Затем мы можем использовать этот `checker` в `Depends(checker)` вместо `Depends(FixedContentQueryChecker)`, потому что зависимостью является экземпляр `checker`, а не сам класс.

И при разрешении зависимости **FastAPI** вызовет `checker` примерно так:

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

                String rawChildModelVersion = childModel.getVersion();

                if (rawChildModelVersion == null) {
                    // Message below is checked for in the MNG-2199 core IT.
                    problems.add(new ModelProblemCollectorRequest(Severity.FATAL, Version.V31)
                            .setMessage("Version must be a constant")

    def __call__(self, q: str = ""):
        if q:
            return self.fixed_content in q
        return False


checker = FixedContentQueryChecker("bar")


@app.get("/query-checker/")
async def read_query_check(fixed_content_included: bool = Depends(checker)):

	if err := DB.Create(&pet).Error; err != nil {
		t.Fatalf("errors happened when create: %v", err)
	}

	CheckPet(t, pet, pet)

	// Find
	var pet2 Pet
	DB.Find(&pet2, "id = ?", pet.ID)
	DB.Model(&pet2).Association("Toy").Find(&pet2.Toy)
	CheckPet(t, pet2, pet)

	// Count
	AssertAssociationCount(t, pet, "Toy", 1, "")

	// Append
	toy := Toy{Name: "toy-has-one-append"}

              files=".*[/\\]plugins[/\\]src[/\\]main[/\\]java[/\\]org[/\\]gradle[/\\]api[/\\]tasks[/\\][^/\\]+"/>
    <suppress checks="JavadocPackage"
              files=".*[/\\]process-services[/\\]src[/\\]main[/\\]java[/\\]org[/\\]gradle[/\\]process[/\\][^/\\]+"/>
    <suppress checks="JavadocPackage"
              files=".*[/\\]plugins[/\\]src[/\\]main[/\\]java[/\\]org[/\\]gradle[/\\]jvm[/\\][^/\\]+"/>

    * Use of hierarchical Pydantic models, Python `typing`’s `List` and `Dict`, etc.
    * And validators allow complex data schemas to be clearly and easily defined, checked and documented as JSON Schema.
    * You can have deeply **nested JSON** objects and have them all validated and annotated.
* **Extensible**:

              public void close() throws IOException {
                super.close();
                counter[0]--;
              }
            };
          }
        };
    byte[] result = ByteSource.concat(checker, checker, checker).read();
    assertThat(result).hasLength(150);
  }

  private void joinHelper(Integer... spans) throws Exception {
    List<ByteSource> sources = new ArrayList<>();
    int start = 0;

not use beta APIs, unless you [repackage] them. **If your
code is a library, we strongly recommend using the [Guava Beta Checker] to
ensure that you do not use any `@Beta` APIs!**

[Guava Beta Checker]: https://github.com/google/guava-beta-checker

<!-- References -->

      } catch (Exception | Error unsafeFailure) { // sneaky checked exception
        thrownUnsafeFailure = unsafeFailure;
        // Catch absolutely everything and fall through to AtomicReferenceFieldUpdaterAtomicHelper.
        try {
          helper = new AtomicReferenceFieldUpdaterAtomicHelper();
        } catch (Exception // sneaky checked exception
            | Error atomicReferenceFieldUpdaterFailure) {

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：