}

  public <T extends Readable & Appendable> void testMultiBound() {
    assertAssignable(new TypeToken<List<T>>() {}, new TypeToken<List<? extends Readable>>() {});
    assertAssignable(new TypeToken<List<T>>() {}, new TypeToken<List<? extends Appendable>>() {});
  }

  public void testToGenericType() {

  }

  public <T extends Readable & Appendable> void testMultiBound() {
    assertAssignable(new TypeToken<List<T>>() {}, new TypeToken<List<? extends Readable>>() {});
    assertAssignable(new TypeToken<List<T>>() {}, new TypeToken<List<? extends Appendable>>() {});
  }

  public void testToGenericType() {

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] *}

It declares an optional query parameter `q` as a `str`, and then it just returns it.

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

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

## Erste Abhängigkeit, „Dependable“

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

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

Diese deklariert einen optionalen Abfrageparameter `q` vom Typ `str` und gibt ihn dann einfach zurück.

## Segunda dependencia, "dependable" y "dependant"

Luego puedes crear otra función de dependencia (un "dependable") que al mismo tiempo declare una dependencia propia (por lo que también es un "dependant"):

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

Centrémonos en los parámetros declarados:

		}
	}
}

func testStorageAPIRenameFile(t *testing.T, storage StorageAPI) {
	err := storage.AppendFile(t.Context(), "foo", "myobject", []byte("foo"))
	if err != nil {
		t.Fatalf("unexpected error %v", err)
	}

	err = storage.AppendFile(t.Context(), "foo", "otherobject", []byte("foo"))
	if err != nil {
		t.Fatalf("unexpected error %v", err)
	}

	testCases := []struct {

	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"))

	// Create test files for further reading.
	for i, appendFile := range appendFiles {
		err = xlStorage.AppendFile(t.Context(), volume, appendFile.fileName, []byte("hello, world"))
		if err != appendFile.expectedErr {
			t.Fatalf("Creating file failed: %d %#v, expected: %s, got: %s", i+1, appendFile, appendFile.expectedErr, err)
		}
	}

	{
		buf := make([]byte, 5)

		t.Fatalf("Creating a volume failed with %s expected to pass.", err)
	}

	// Attempt to create a file to verify the permissions later.
	// AppendFile creates file with 0666 perms.
	if err = disk.AppendFile(t.Context(), testCase.volName, pathJoin("hello-world.txt", xlStorageFormatFile), []byte("Hello World")); err != nil {
		t.Fatalf("Create a file `test` failed with %s expected to pass.", err)
	}

# Security Tools

When you need to declare dependencies with OAuth2 scopes you use `Security()`.

But you still need to define what is the dependable, the callable that you pass as a parameter to `Depends()` or `Security()`.

There are multiple tools that you can use to create those dependables, and they get integrated into OpenAPI so they are shown in the automatic docs UI, they can be used by automatically generated clients and SDKs, etc.