if (IPV4_DELIMITER_MATCHER.countIn(ipString) + 1 != IPV4_PART_COUNT) {
      return null; // Wrong number of parts
    }

    byte[] bytes = new byte[IPV4_PART_COUNT];
    int start = 0;
    // Iterate through the parts of the ip string.
    // Invariant: start is always the beginning of an octet.
    for (int i = 0; i < IPV4_PART_COUNT; i++) {

apps may target different 'environments' which contain different instances and variants of Istio.

- Better security: separate Istio components reside in different namespaces, allowing different teams or
roles to manage different parts of Istio. For example, a security team would maintain the
root CA and policy, a telemetry team may only have access to Prometheus,
and a different team may maintain the control plane components (which are highly security sensitive).

		// Failed to upload object part, abort.
		t.Fatalf("%s : %s", instanceType, err.Error())
	}

	// Complete multipart.
	parts := []CompletePart{
		{ETag: etag1, PartNumber: 1},
		{ETag: etag2, PartNumber: 2},
	}
	_, err = obj.CompleteMultipartUpload(context.Background(), bucket, object, uploadID, parts, ObjectOptions{})
	if err != nil {
		// Failed to complete multipart upload, abort.
		t.Fatalf("%s : %s", instanceType, err.Error())

{!../../docs_src/app_testing/test_main.py!}
```

...and have the code for the tests just like before.

## Testing: extended example

Now let's extend this example and add more details to see how to test different parts.

### Extended **FastAPI** app file

Let's continue with the same file structure as before:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

    }

    when {
      secondSpace != -1 && firstSpace == CLEAN.length && line.startsWith(CLEAN) -> {
        val parts =
          line.substring(secondSpace + 1)
            .split(' ')
        entry.readable = true
        entry.currentEditor = null
        entry.setLengths(parts)
      }

      secondSpace == -1 && firstSpace == DIRTY.length && line.startsWith(DIRTY) -> {

## Requirements

FastAPI stands on the shoulders of giants:

* <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> for the web parts.
* <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> for the data parts.

## Installation

// which is allowed for by the PAX specification, but not always portable.
func parsePAXTime(s string) (time.Time, error) {
	const maxNanoSecondDigits = 9

	// Split string into seconds and sub-seconds parts.
	ss, sn, _ := strings.Cut(s, ".")

	// Parse the seconds.
	secs, err := strconv.ParseInt(ss, 10, 64)
	if err != nil {
		return time.Time{}, ErrHeader
	}
	if len(sn) == 0 {

# Simple OAuth2 with Password and Bearer

Now let's build from the previous chapter and add the missing parts to have a complete security flow.

## Get the `username` and `password`

We are going to use **FastAPI** security utilities to get the `username` and `password`.

OAuth2 specifies that when using the "password flow" (that we are using) the client/user must send a `username` and `password` fields as form data.

		TransitionStatus: "",
		DataDir:          "bffea160-ca7f-465f-98bc-9b4f1c3ba1ef",
		XLV1:             false,
		ModTime:          time.Now(),
		Size:             0,
		Mode:             0,
		Metadata:         nil,
		Parts:            nil,
		Erasure: ErasureInfo{
			Algorithm:    ReedSolomon.String(),
			DataBlocks:   4,
			ParityBlocks: 2,
			BlockSize:    10000,
			Index:        1,
			Distribution: []int{1, 2, 3, 4, 5, 6, 7, 8},

	if objInfo.ModTime.IsZero() || objInfo.ModTime.Equal(time.Unix(0, 0)) {
		return false
	}

	// Check if the part number is correct.
	if opts.PartNumber > 1 {
		partFound := false
		for _, pi := range objInfo.Parts {
			if pi.Number == opts.PartNumber {
				partFound = true
				break
			}
		}
		if !partFound {
			// According to S3 we don't need to set any object information here.