// JoinLoaders - joins multiple loaders into a single loader. The returned
// loader will call each of the given loaders in order. If any of the loaders
// return an error, the returned loader will return that error.
func JoinLoaders(loaders ...MetricsLoaderFn) MetricsLoaderFn {
	return func(ctx context.Context, m MetricValues, c *metricsCache) error {
		for _, loader := range loaders {
			if err := loader(ctx, m, c); err != nil {

}

// Apply applies the SSE bucket configuration on the given HTTP headers and
// sets the specified SSE headers.
//
// Apply does not overwrite any existing SSE headers. Further, it will
// set minimal SSE-KMS headers if autoEncrypt is true and the BucketSSEConfig
// is nil.
func (b *BucketSSEConfig) Apply(headers http.Header, opts ApplyOptions) {
	if crypto.Requested(headers) {
		return
	}
	if b == nil {
		if opts.AutoEncrypt {

        method = self.METHOD

        def fetch_credentials():
            # HTTP headers are case insensitive filter out
            # all duplicate headers and pick one.
            headers = {}
            headers['content-type'] = 'application/x-www-form-urlencoded'
            headers['authorization'] = urllib3.make_headers(
                basic_auth='%s:%s' % (self.cid, self.csec))['authorization']

	// ErrIncompatibleEncryptionMethod indicates that both SSE-C headers and SSE-S3 headers were specified, and are incompatible
	// The client needs to remove the SSE-S3 header or the SSE-C headers
	ErrIncompatibleEncryptionMethod = Errorf("Server side encryption specified with both SSE-C and SSE-S3 headers")

	extractedSignedHeaders := make(http.Header)
	for _, header := range signedHeaders {
		// `host` will not be found in the headers, can be found in r.Host.
		// but its always necessary that the list of signed headers containing host in it.
		val, ok := reqHeaders[http.CanonicalHeaderKey(header)]
		if !ok {
			// try to set headers from Query String
			val, ok = reqQueries[header]
		}
		if ok {

		closeBitrotWriters(writers)
		if err != nil {
			t.Fatalf("Test %d: failed to create random test data: %v", i, err)
		}

		readers := make([]io.ReaderAt, len(disks))
		for i, disk := range disks {
			shardFilesize := erasure.ShardFileSize(test.size)
			readers[i] = newBitrotReader(disk, nil, "testbucket", "testobject", shardFilesize, test.algorithm, bitrotWriterSum(writers[i]), erasure.ShardSize())
		}

//
// Header specification:
// Continuation messages contain two headers, as follows:
// https://docs.aws.amazon.com/AmazonS3/latest/API/images/s3select-frame-diagram-cont.png
//
// Payload specification:
// Continuation messages have no payload.
var continuationMessage = []byte{
	0, 0, 0, 57, // total byte-length.
	0, 0, 0, 41, // headers byte-length.
	139, 161, 157, 242, // prelude crc.

					i, o, l, skip, sn, ps, oRef, lRef, skipRef, snRef, psRef)
			}
		}

	}
}

var getDefaultOptsTests = []struct {
	headers        http.Header
	copySource     bool
	metadata       map[string]string
	encryptionType encrypt.Type
	err            error
}{
	{
		headers: http.Header{
			xhttp.AmzServerSideEncryptionCustomerAlgorithm: []string{"AES256"},

    signatureVersion: 'v4'
});

// List all contents stored in the zip archive
s3.listObjectsV2({Bucket : 'your-bucket', Prefix: 'path/to/file.zip/'}).
    on('build', function(req) { req.httpRequest.headers['X-Minio-Extract'] = 'true'; }).
    send(function(err, data) {
        if (err) {
            console.log("Error", err);
        } else {
            console.log("Success", data);
        }
    });

	Type() types.TargetType
}

var (

	// systemTargets is the set of enabled loggers.
	// Must be immutable at all times.
	// Can be swapped to another while holding swapMu
	systemTargets  = []Target{}
	swapSystemMuRW sync.RWMutex

	// auditTargets is the list of enabled audit loggers
	// Must be immutable at all times.
	// Can be swapped to another while holding swapMu
	auditTargets  = []Target{}