## Context Managers { #context-managers }

### What are "Context Managers" { #what-are-context-managers }

"Context Managers" are any of those Python objects that you can use in a `with` statement.

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"context"
	"os"
	"reflect"
	"sync"
	"testing"

	"github.com/minio/minio/internal/dsync"
)

// Helper function to create a lock server for testing
func createLockTestServer(ctx context.Context, t *testing.T) (string, *lockRESTServer, string) {
	obj, fsDir, err := prepareFS(ctx)
	if err != nil {
		t.Fatal(err)

    }

    @Test
    @DisplayName("seq ctor: tag 3 with wrong tag class is rejected")
    void sequenceConstructor_ticketTag_wrongClass_throws() {
        // Arrange: minimal valid fields + tag 3 as CONTEXT-SPECIFIC instead of APPLICATION
        ASN1EncodableVector v = new ASN1EncodableVector();
        v.add(new DERTaggedObject(true, 0, new ASN1Integer(Integer.parseInt(KerberosConstants.KERBEROS_VERSION))));

      Logger logger = logger(context);
      if (logger.isLoggable(Level.SEVERE)) {
        logger.log(Level.SEVERE, message(context), exception);
      }
    }

    private static Logger logger(SubscriberExceptionContext context) {
      return Logger.getLogger(EventBus.class.getName() + "." + context.getEventBus().identifier());
    }

}

// client to talk to bootstrap NEndpoints.
type bootstrapRESTClient struct {
	gridConn *grid.Connection
}

// Verify function verifies the server config.
func (client *bootstrapRESTClient) Verify(ctx context.Context, srcCfg *ServerSystemConfig) (err error) {
	if newObjectLayerFn() != nil {
		return nil
	}

	recvCfg, err := serverVerifyHandler.Call(ctx, client.gridConn, grid.NewMSS())
	if err != nil {
		return err

 * </pre>
 *
 * </td>
 * <td>
 * Open the Named Pipe foo for reading and writing. The pipe will behave like the <code>CallNamedPipe</code> interface.
 * </td>
 * </tr>
 * <tr>
 * <td >
 *
 * <pre>
 * new SmbNamedPipe("smb://server/IPC$/foo", SmbNamedPipe.PIPE_TYPE_RDWR | SmbNamedPipe.PIPE_TYPE_TRANSACT, context);
 * </pre>
 *
 * </td>
 * <td>

package cmd

import (
	"context"
	"fmt"
	"io"
)

// Writes to multiple writers
type multiWriter struct {
	writers     []io.Writer
	writeQuorum int
	errs        []error
}

// Write writes data to writers.
func (p *multiWriter) Write(ctx context.Context, blocks [][]byte) error {
	for i := range p.writers {
		if p.errs[i] != nil {
			continue
		}

		buffer := make([]byte, len(data), 2*len(data))
		copy(buffer, data)

		erasure, err := NewErasure(t.Context(), test.dataBlocks, test.parityBlocks, blockSizeV2)
		if err != nil {
			t.Fatalf("Test %d: failed to create erasure: %v", i, err)
		}
		encoded, err := erasure.EncodeData(t.Context(), buffer)
		if err != nil {
			t.Fatalf("Test %d: failed to encode data: %v", i, err)
		}

		"Cluster object version count distribution", "range")
)

// loadClusterUsageObjectMetrics - reads cluster usage metrics.
//
// This is a `MetricsLoaderFn`.
func loadClusterUsageObjectMetrics(ctx context.Context, m MetricValues, c *metricsCache) error {
	dataUsageInfo, err := c.dataUsageInfo.Get()
	if err != nil {
		metricsLogIf(ctx, err)
		return nil
	}

	// data usage has not captured any data yet.

	storageClass     string
	bucketName       string
	enableSha256     bool
	enableMultipart  bool
	creds            auth.Credentials
}

// Get the max throughput and iops numbers.
func objectSpeedTest(ctx context.Context, opts speedTestOpts) chan madmin.SpeedTestResult {
	ch := make(chan madmin.SpeedTestResult, 1)
	go func() {
		defer xioutil.SafeClose(ch)

		concurrency := opts.concurrencyStart

		if opts.autotune {