StringBuilder sb1FromIterator = new StringBuilder().append('x');
    joiner.appendTo(sb1FromIterator, parts.iterator());
    assertEquals("x" + expected, sb1FromIterator.toString());

    // The use of iterator() works around J2KT b/381065164.
    Integer[] partsArray = newArrayList(parts.iterator()).toArray(new Integer[0]);
    assertEquals(expected, joiner.join(partsArray));

    StringBuilder sb2 = new StringBuilder().append('x');

Let's use the tools provided by **FastAPI** to handle security.

## How it looks { #how-it-looks }

Let's first just use the code and see how it works, and then we'll come back to understand what's happening.

## Create `main.py` { #create-main-py }

Copy the example in a file `main.py`:

{* ../../docs_src/security/tutorial001_an_py39.py *}

## Run it { #run-it }

        }

        verify(autoCloseTree).close();
    }

    /**
     * Test for unwrap with nested wrapping.
     * Verifies that unwrap works correctly with multiple levels of wrapping.
     */
    @Test
    void testUnwrap_nestedWrapping() {
        // Create a chain of wrapped trees
        CustomSmbTree innerTree = mock(CustomSmbTree.class);

    .heldCertificate(localhostCertificate)
    .build();
MockWebServer server = new MockWebServer();
server.useHttps(serverCertificates.sslSocketFactory(), false);
```

`HandshakeCertificates` also works for clients where its job is to define which root certificates
to trust. In this simplified example we trust the server's self-signed certificate:

```java

      byte[] got = out.toByteArray();
      for (int i = 0; i < expected.length; i++) {
        assertEquals(expected[i], got[i]);
      }
    }
  }

  // Assumes that AbstractNonStreamingHashFunction works properly (must be tested elsewhere!)
  private static class Control extends AbstractNonStreamingHashFunction {
    @Override
    public HashCode hashBytes(byte[] input, int off, int len) {

    @BeforeEach
    void setUp() throws Exception {
        source = new Source();

        projectArtifact = createArtifactSpec("project", "1.0", null);
    }

    @Test
    @Disabled("works, but we don't fail on cycles presently")
    void testCircularDependencyNotIncludingCurrentProject()
            throws ArtifactResolutionException, InvalidVersionSpecificationException {

```console
// Создать директорию "Code"
$ mkdir code
// Перейти в эту директорию
$ cd code
```

...и пример кода на Python...

```Python
wont_work()  # Это не сработает 😱
works(foo="bar")  # Это работает 🎉
```

...и на этом всё.

////

//// tab | Информация

Код в блоках кода не должен изменяться, за исключением комментариев.

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

///

expanded total storage by _(newly_added_servers\*m)_ more drives, taking the total count to _(existing_servers\*m)+(newly_added_servers\*m)_ drives. New object upload requests automatically start using the least used cluster. This expansion strategy works endlessly, so you can perpetually expand your clusters as needed.  When you restart, it is immediate and non-disruptive to the applications. Each group of servers in the command-line is called a pool. There are 2 server pools in this example. New objects...

    Response originalResponse = chain.proceed(chain.request());
    return originalResponse.newBuilder()
        .header("Cache-Control", "max-age=60")
        .build();
  }
};
```