defaultSha256Cksum = emptySHA256
		v, ok = r.Header[xhttp.AmzContentSha256]
	}

	// We found 'X-Amz-Content-Sha256' return the captured value.
	if ok {
		return v[0]
	}

	// We couldn't find 'X-Amz-Content-Sha256'.
	return defaultSha256Cksum
}

// isValidRegion - verify if incoming region value is valid with configured Region.
func isValidRegion(reqRegion string, confRegion string) bool {

	}

	ignoredErrs := []error{
		errFileNotFound,
		errVolumeNotFound,
		errFileVersionNotFound,
		io.ErrUnexpectedEOF, // some times we would read without locks, ignore these errors
		io.EOF,              // some times we would read without locks, ignore these errors
		context.DeadlineExceeded,
		context.Canceled,
	}
	ignoredErrs = append(ignoredErrs, objectOpIgnoredErrs...)

	errs := g.Wait()

	c.Assert(response.ContentLength, int64(len([]byte("hello world"))))
	var buffer2 bytes.Buffer
	// retrieve the contents of response body.
	n, err := io.Copy(&buffer2, response.Body)
	c.Assert(err, nil)
	c.Assert(n, int64(len([]byte("hello world"))))
	// asserted the contents of the fetched object with the expected result.
	c.Assert(true, bytes.Equal(buffer2.Bytes(), []byte("hello world")))

		// we are inside a for loop i.e if we use defer, we would accumulate a lot of open files by the time
		// we return from this function.
		closeBitrotReaders(readers)
		if err != nil {
			// If we have successfully written all the content that was asked
			// by the client, but we still see an error - this would mean
			// that we have some parts or data blocks missing or corrupted

2018/12/26 17:49:36 listening on http://localhost:8080/
```

> NOTE: for a reasonable test outcome, make sure the assumed user has at least permission/policy to list all buckets. That policy would look like below:

```
{
  "version": "2012-10-17",
  "statement": [
    {
      "effect": "Allow",
      "action": [
        "s3:ListAllMyBuckets"
      ],
      "resource": [

	r := &http.Request{
		Proto:  "HTTP/1.0",
		Method: http.MethodPost,
		URL:    u,
	}
	if !guessIsRPCReq(r) {
		t.Fatal("Test shouldn't fail for a possible net/rpc request.")
	}
	r = &http.Request{
		Proto:  "HTTP/1.1",
		Method: http.MethodGet,
	}
	if guessIsRPCReq(r) {
		t.Fatal("Test shouldn't report as net/rpc for a non net/rpc request.")
	}
	r = &http.Request{
		Proto:  "HTTP/1.1",
		Method: http.MethodGet,

## Concepts

- If an object is under legal hold, it cannot be deleted unless the legal hold is explicitly removed for the respective version id. DeleteObjectVersion() would fail otherwise.

```
KEY:
etcd  federate multiple clusters for IAM and Bucket DNS

	}

	eventData, eErr := target.store.Get(key.Name)
	if eErr != nil {
		// The last event key in a successful batch will be sent in the channel atmost once by the replayEvents()
		// Such events will not exist and would've been already been sent successfully.
		if os.IsNotExist(eErr) {
			return nil
		}
		return eErr
	}

	if err := target.send(eventData); err != nil {
		if xnet.IsNetworkOrHostDown(err, false) {

CAREFUL: When utilizing two-way communication, it is important to ensure that the remote handler is not blocked on a send.
If the remote handler is blocked on a send, and the client is trying to send without the remote receiving, 
the operation would become deadlocked if the channels are full.

### Typed handlers

Typed handlers are handlers that have a specific type for the request and response payloads.

```go
    // Create a typed handler.