##### Figure 1 - Secure Channel construction

```
plaintext   := chunk_0          ||       chunk_1          ||       chunk_2          ||       ...
                 |                         |                         |
                 |                         |                         |
               AEAD <- key, nonce + 0    AEAD <- key, nonce + 1    AEAD <- key, nonce + 2    ...

			return
		}
		copy(objectEncryptionKey[:], key)

		var nonce [12]byte
		tmp := sha256.Sum256(fmt.Append(nil, uploadID, partID))
		copy(nonce[:], tmp[:12])

		partEncryptionKey := objectEncryptionKey.DerivePartKey(uint32(partID))
		encReader, err := sio.EncryptReader(reader, sio.Config{
			Key:   partEncryptionKey[:],
			Nonce: &nonce,
		})
		if err != nil {

	//   return len(e) > 16 && !bytes.ContainsRune(e, '-')
	//
	// An encrypted ETag may contain some random bytes - e.g.
	// and nonce value. This nonce value may contain a '-'
	// just by its nature of being randomly generated.
	// The above implementation would incorrectly consider
	// such an ETag (with a nonce value containing a '-')
	// as non-encrypted.

	return len(e) >= 32 // We consider all ETags longer than 32 bytes as encrypted
}

        def query_example(
            data: Union[str, None] = Query(
                default=None,
                example="query1",
            ),
        ):
            return data

    @app.get("/query_examples/")
    def query_examples(
        data: Union[str, None] = Query(
            default=None,
            examples=["query1", "query2"],
        ),
    ):

say_hi()  # Oh, no, this throws an error! 😱
```

The `name` parameter is **still required** (not *optional*) because it doesn't have a default value. Still, `name` accepts `None` as the value:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

The good news is, once you are on Python 3.10 you won't have to worry about that, as you will be able to simply use `|` to define unions of types:

    ),
    READY_FOR_RELEASE("Ready for Release", "Once a day: Rerun tests in more environments", "ReadyforRelease"),
    WEEKLY_VALIDATION(
        "Weekly Validation",
        "Once a week: Run tests in even more environments but less often",
        "WeeklyValidation",
    ),
    HISTORICAL_PERFORMANCE(
        "Historical Performance",
        "Once a week: Run performance tests for multiple Gradle versions",

@REM Execute a user defined script before this one
if not "%MAVEN_SKIP_RC%"=="" goto skipRc
if exist "%PROGRAMDATA%\mavenrc.cmd" call "%PROGRAMDATA%\mavenrc.cmd" %*
@REM check for pre script, once with legacy .bat ending and once with .cmd ending
if exist "%USERPROFILE%\mavenrc_pre.bat" echo Warning: The mavenrc_pre.bat script is deprecated and will be removed in a future version. >&2

                       var_name,
                       query_item,
                       enabled_by_default,
                       question=None,
                       yes_reply=None,
                       no_reply=None,
                       bazel_config_name=None):
  """Set boolean action_env variable.

  Ask user if query_item will be enabled. Default is used if no input is given.

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):

	"errors"
	"fmt"
	"log"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/minio/minio/internal/event"
	"github.com/minio/minio/internal/logger"
	"github.com/minio/minio/internal/once"
	"github.com/minio/minio/internal/store"
	xnet "github.com/minio/pkg/v3/net"

	"github.com/IBM/sarama"
	saramatls "github.com/IBM/sarama/tools/tls"
)

// Kafka input constants
const (