{* ../../docs_src/pydantic_v1_in_v2/tutorial004_an_py310.py hl[4,18] *}

### Migrate in steps { #migrate-in-steps }

/// tip

First try with `bump-pydantic`, if your tests pass and that works, then you're done in one command. ✨

///

If `bump-pydantic` doesn't work for your use case, you can use the support for both Pydantic v1 and v2 models in the same app to do the migration to Pydantic v2 gradually.

    Object one = new Object();
    assertThat(map.put(one, one)).isNull();
    assertThat(map.get(one)).isSameInstanceAs(one);
    assertThat(map.containsKey(one)).isTrue();
    assertThat(map.containsValue(one)).isTrue();
    Object two = new Object();
    assertThat(map.replace(one, two)).isSameInstanceAs(one);
    assertThat(map.containsKey(one)).isTrue();

catch() {
	if [ $# -ne 0 ]; then
		echo "error on line $1"
		for site in sitea siteb; do
			echo "$site server logs ========="
			cat "/tmp/${site}_1.log"
			echo "==========================="
			cat "/tmp/${site}_2.log"
		done
	fi

	echo "Cleaning up instances of MinIO"
	pkill minio
	pkill -9 minio
	rm -rf /tmp/multisitea
	rm -rf /tmp/multisiteb
	rm -rf /tmp/data
	if [ $# -ne 0 ]; then
		exit $#
	fi
}

catch

	}

	opts := madmin.DriveSpeedTestOpts{
		Serial:    serial,
		BlockSize: blockSize,
		FileSize:  fileSize,
	}

	done := keepHTTPResponseAlive(w)
	result := driveSpeedTest(r.Context(), opts)
	done(nil)

	peersLogIf(r.Context(), gob.NewEncoder(w).Encode(result))
}

// GetReplicationMRFHandler - returns replication MRF for bucket

	disks := er.getDisks()
	var wg sync.WaitGroup
	var mu sync.Mutex
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for _, i := range r.Perm(len(disks)) {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if disks[i] == nil {
				return
			}
			di, err := disks[i].DiskInfo(context.Background(), DiskInfoOptions{})
			if err != nil || di.Healing {
				// - Do not consume disks which are not reachable

			if val := globalServiceFreeze.Load(); val != nil {
				if unlock, ok := val.(chan struct{}); ok && unlock != nil {
					// Wait until unfrozen.
					select {
					case <-unlock:
					case <-r.Context().Done():
						// if client canceled we don't need to wait here forever.
						return
					}
				}
			}
		}

		globalHTTPStats.addRequestsInQueue(1)
		pool := globalAPIConfig.getRequestsPool()

}

func (bs *bootstrapTracer) Publish(ctx context.Context, trace *pubsub.PubSub[madmin.TraceInfo, madmin.TraceType]) {
	for _, bsEvent := range bs.Events() {
		if bsEvent.Message != "" {
			select {
			case <-ctx.Done():
			default:
				trace.Publish(bsEvent)
			}
		}
	}

				defer xioutil.SafeClose(updates)
				// Start update collector.
				go func() {
					defer wg.Done()
					for info := range updates {
						mu.Lock()
						results[i] = info
						mu.Unlock()
					}
				}()
				// Start scanner. Blocks until done.
				err := erObj.nsScanner(ctx, allBuckets, wantCycle, updates, healScanMode)
				if err != nil {
					scannerLogIf(ctx, err)

    echo \"Failed attempts: $ATTEMPTS\" ;
    if [ $ATTEMPTS -gt $LIMIT ]; then
      exit 1 ;
    fi ;
    sleep 2 ; # 1 second intervals between attempts
    $MC_COMMAND ;
    STATUS=$? ;
  done ;
  set -e ; # reset `e` as active
  return 0
}

# checkPolicyExists ($policy)
# Check if the policy exists, by using the exit code of `mc admin policy info`
checkPolicyExists() {
  POLICY=$1

//
// Subsequently this allows golang http RoundTripper
// to reuse the same connection for future requests.
func DrainBody(respBody io.ReadCloser) {
	// Callers should close resp.Body when done reading from it.
	// If resp.Body is not closed, the Client's underlying RoundTripper
	// (typically Transport) may not be able to reuse a persistent TCP
	// connection to the server for a subsequent "keep-alive" request.