} else {
				m[supportedHeader] = strings.Join(value, ",")
			}
		}
	}

	for key := range v {
		for _, prefix := range userMetadataKeyPrefixes {
			if !stringsHasPrefixFold(key, prefix) {
				continue
			}
			value, ok := nv[http.CanonicalHeaderKey(key)]
			if ok {
				m[key] = strings.Join(value, ",")
				break
			}
		}
	}
	return nil
}

}
```

#### Unpacking a `dict` { #unpacking-a-dict }

If we take a `dict` like `user_dict` and pass it to a function (or class) with `**user_dict`, Python will "unpack" it. It will pass the keys and values of the `user_dict` directly as key-value arguments.

So, continuing with the `user_dict` from above, writing:

```Python
UserInDB(**user_dict)
```

would result in something equivalent to:

```Python
UserInDB(

    private boolean parallel;

    /**
     * Plugin context keyed by project ({@link MavenProject#getId()}) and by plugin lookup key
     * ({@link PluginDescriptor#getPluginLookupKey()}). Plugin contexts itself are mappings of {@link String} keys to
     * {@link Object} values.
     */
    private final ConcurrentMap<String, ConcurrentMap<String, ConcurrentMap<String, Object>>>

	// PAXRecords is a map of PAX extended header records.
	//
	// User-defined records should have keys of the following form:
	//	VENDOR.keyword
	// Where VENDOR is some namespace in all uppercase, and keyword may
	// not contain the '=' character (e.g., "GOLANG.pkg.version").
	// The key and value should be non-empty UTF-8 strings.
	//
	// When Writer.WriteHeader is called, PAX records derived from the

	// JWT token for x-amz-security-token is signed with admin
	// secret key, temporary credentials become invalid if
	// server admin credentials change. This is done to ensure
	// that clients cannot decode the token using the temp
	// secret keys and generate an entirely new claim by essentially
	// hijacking the policies. We need to make sure that this is

package handlers

import (
	"net"
	"net/http"
	"regexp"
	"strings"

	"github.com/minio/minio/internal/config"
	"github.com/minio/pkg/v3/env"
)

var (
	// De-facto standard header keys.
	xForwardedFor    = http.CanonicalHeaderKey("X-Forwarded-For")
	xForwardedHost   = http.CanonicalHeaderKey("X-Forwarded-Host")
	xForwardedPort   = http.CanonicalHeaderKey("X-Forwarded-Port")

		return []string{}, err
	}

	// We map keys that correspond to LDAP DNs and validate that they exist in
	// the LDAP server.
	dnValidator := sys.LDAPConfig.GetValidatedUserDN
	if isGroup {
		dnValidator = sys.LDAPConfig.GetValidatedGroupDN
	}

	// map of normalized DN keys to original keys.
	normalizedDNKeysMap := make(map[string][]string)
	var collectedErrors []error

		}

		expectedETaghex := getMD5Hash([]byte(randomString))

		key := "obj" + strconv.Itoa(i)
		objects[key] = []byte(randomString)
		metadata := make(map[string]string)
		metadata["etag"] = expectedETaghex
		var objInfo ObjectInfo

	if err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

	writeSuccessNoContent(w)
}

// InfoAccessKey - GET /minio/admin/v3/info-access-key?access-key=<access-key>
func (a adminAPIHandlers) InfoAccessKey(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()

	// preceding the original header. This file contains a set of key-value
	// records, which are used to overcome USTAR's shortcomings, in addition to
	// providing the ability to have sub-second resolution for timestamps.
	//
	// Some newer formats add their own extensions to PAX by defining their
	// own keys and assigning certain semantic meaning to the associated values.