func (h Header) allowedFormats() (format Format, paxHdrs map[string]string, err error) {
	format = FormatUSTAR | FormatPAX | FormatGNU
	paxHdrs = make(map[string]string)

	var whyNoUSTAR, whyNoPAX, whyNoGNU string
	var preferPAX bool // Prefer PAX over USTAR
	verifyString := func(s string, size int, name, paxKey string) {
		// NUL-terminator is optional for path and linkpath.

 *  **API Change**: Use `IOException` in `Callback.onFailure()`. This is
    a source-incompatible change, and is different from OkHttp 2.0.0-RC2 which
    used `Throwable`.
 *  Fix: Fixed a caching bug where we weren't storing rewritten request headers
    like `Accept-Encoding`.
 *  Fix: Fixed bugs in handling the SPDY window size. This was stalling certain
    large downloads

Details about the `async def` syntax for *path operation functions* and some background about asynchronous code, concurrency, and parallelism.

## In a hurry? { #in-a-hurry }

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

```Python
results = await some_library()
```

	if s3Err == ErrNone && retentionMode.Valid() {
		metadata[strings.ToLower(xhttp.AmzObjectLockMode)] = string(retentionMode)
		metadata[strings.ToLower(xhttp.AmzObjectLockRetainUntilDate)] = amztime.ISO8601Format(retentionDate.UTC())
	}
	if s3Err == ErrNone && legalHold.Status.Valid() {
		metadata[strings.ToLower(xhttp.AmzObjectLockLegalHold)] = string(legalHold.Status)
	}
	if s3Err != ErrNone {

   */
  public MediaType withParameters(String attribute, Iterable<String> values) {
    checkNotNull(attribute);
    checkNotNull(values);
    String normalizedAttribute = normalizeToken(attribute);
    ImmutableListMultimap.Builder<String, String> updatedParameters =
        ImmutableListMultimap.builder();
    for (Entry<String, String> entry : parameters.entries()) {
      String key = entry.getKey();

   */
  public MediaType withParameters(String attribute, Iterable<String> values) {
    checkNotNull(attribute);
    checkNotNull(values);
    String normalizedAttribute = normalizeToken(attribute);
    ImmutableListMultimap.Builder<String, String> updatedParameters =
        ImmutableListMultimap.builder();
    for (Entry<String, String> entry : parameters.entries()) {
      String key = entry.getKey();

// header values specified in X-Amz-Metadata-Directive.
func getCpObjMetadataFromHeader(ctx context.Context, r *http.Request, userMeta map[string]string) (map[string]string, error) {
	// Make a copy of the supplied metadata to avoid
	// to change the original one.
	defaultMeta := make(map[string]string, len(userMeta))
	for k, v := range userMeta {
		// skip tier metadata when copying metadata from source object
		switch k {

	FMOVD.W	8(R1), F20                                      // 348c40fc
	FMOVQ.P	11(R10), F13                                    // 4db5c03c
	FMOVQ.W	11(R20), F15                                    // 8fbec03c

// storing $0 to memory, $0 will be replaced with ZR.
	MOVD	$0, (R1)  // 3f0000f9
	MOVW	$0, (R1)  // 3f0000b9
	MOVWU	$0, (R1)  // 3f0000b9
	MOVH	$0, (R1)  // 3f000079
	MOVHU	$0, (R1)  // 3f000079
	MOVB	$0, (R1)  // 3f000039

		}
	}
}

func (z *erasureServerPools) NewNSLock(bucket string, objects ...string) RWLocker {
	return z.serverPools[0].NewNSLock(bucket, objects...)
}

// GetDisksID will return disks by their ID.
func (z *erasureServerPools) GetDisksID(ids ...string) []StorageAPI {
	idMap := make(map[string]struct{}, len(ids))
	for _, id := range ids {
		idMap[id] = struct{}{}
	}

	loadPolicyDoc(ctx context.Context, policy string, m map[string]PolicyDoc) error
	loadPolicyDocWithRetry(ctx context.Context, policy string, m map[string]PolicyDoc, retries int) error
	loadPolicyDocs(ctx context.Context, m map[string]PolicyDoc) error
	loadUser(ctx context.Context, user string, userType IAMUserType, m map[string]UserIdentity) error
	loadSecretKey(ctx context.Context, user string, userType IAMUserType) (string, error)