names := make([][]string, 0)
	/// part, verID, file
	files := make([]map[string][]string, 0)
	partNums := make(map[int]int)
	for k, v := range all {
		for _, file := range v {
			part := getPartNum(file)
			partIdx, ok := partNums[part]
			if !ok {
				partIdx = len(names)
				partNums[part] = partIdx
				names = append(names, nil)

		// objects.
		// Therefore, we remember which objects (there index)
		// in the current batch are single-part SSE-S3 objects.
		metadata = metadata[:0:N]
		buckets = buckets[:0:N]
		names = names[:0:N]
		SSES3SinglePartObjects := make(map[int]bool)
		for i, object := range batch {
			if kind, ok := crypto.IsEncrypted(object.UserDefined); ok && kind == crypto.S3 && !crypto.IsMultiPart(object.UserDefined) {

      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

```

If provided, the auth token parameter is sent as an authorization header.

`MINIO_IDENTITY_PLUGIN_ROLE_POLICY` is a required parameter and can be list of comma separated policy names.

{* ../../docs_src/advanced_middleware/tutorial002.py hl[2,6:8] *}

The following arguments are supported:

* `allowed_hosts` - A list of domain names that should be allowed as hostnames. Wildcard domains such as `*.example.com` are supported for matching subdomains. To allow any hostname either use `allowed_hosts=["*"]` or omit the middleware.

 *       you can set {@code
 *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
 *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
 *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
 *       list.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>

 *       you can set {@code
 *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
 *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
 *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
 *       list.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>