## Utilize a instância como dependência { #use-the-instance-as-a-dependency }

Então, nós podemos utilizar este `checker` em um `Depends(checker)`, no lugar de `Depends(FixedContentQueryChecker)`, porque a dependência é a instância, `checker`, e não a própria classe.

E quando a dependência for resolvida, o **FastAPI** chamará este `checker` como:

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

		}

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

		pet.Toy.Name += "new"
		if err := DB.Save(&pet).Error; err != nil {
			t.Fatalf("errors happened when update: %v", err)
		}

		var pet3 Pet
		DB.Preload("Toy").Find(&pet3, "id = ?", pet.ID)
		CheckPet(t, pet2, pet3)

		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)))

    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: Annotated[bool, Depends(checker)]):

    "path,expected_status,expected_response",
    [
        (
            "/query-checker/",
            200,
            {"fixed_content_in_query": False},
        ),
        (
            "/query-checker/?q=qwerty",
            200,
            {"fixed_content_in_query": False},
        ),
        (
            "/query-checker/?q=foobar",
            200,
            {"fixed_content_in_query": 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" />

These custom validators are for things that can be checked with **only** the **same data** provided in the request.

///

### Understand that Code { #understand-that-code }

	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)
	}

## Die Instanz als Abhängigkeit verwenden { #use-the-instance-as-a-dependency }

Dann könnten wir diesen `checker` in einem `Depends(checker)` anstelle von `Depends(FixedContentQueryChecker)` verwenden, da die Abhängigkeit die Instanz `checker` und nicht die Klasse selbst ist.

Und beim Auflösen der Abhängigkeit ruft **FastAPI** diesen `checker` wie folgt auf:

```Python

            for (String s : footer) {
                writer.writeln(s);
            }
        }
        writer.flush();
    }

    /**
     * Checks if parts of the passed in comment can be used as header comment.
     * This method checks whether a header comment can be defined (i.e. whether
     * this is the first comment in the loaded file). If this is the case, it is