buf        []byte          // Holds bit-rot verified data
}

func (b *wholeBitrotReader) ReadAt(buf []byte, offset int64) (n int, err error) {
	if b.buf == nil {
		b.buf = make([]byte, b.tillOffset-offset)
		if _, err := b.disk.ReadFile(context.TODO(), b.volume, b.filePath, offset, b.buf, b.verifier); err != nil {
			return 0, err
		}
	}
	if len(b.buf) < len(buf) {
		return 0, errLessData
	}

	}
	if err = newTestConfig(globalMinioDefaultRegion, obj); err != nil {
		t.Fatalf("unable initialize config file, %s", err)
	}

	locker := &lockRESTServer{
		ll: &localLocker{
			mutex:   sync.Mutex{},
			lockMap: make(map[string][]lockRequesterInfo),
		},
	}
	creds := globalActiveCred
	token, err := authenticateNode(creds.AccessKey, creds.SecretKey)
	if err != nil {
		t.Fatal(err)
	}
	return fsDir, locker, token
}

     * to avoid the extra class for the lambda (and maybe more for memoizingSupplier itself) and the
     * indirection.
     *
     * One thing to *avoid* is a change to make each Logger user use memoizingSupplier directly:
     * That may introduce an extra class for each lambda (currently a dozen).
     */
    Logger local = logger;
    if (local != null) {
      return local;
    }

      null
    }

  override fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager? {
    // Not supported due to access checks on JDK 9+:
    // java.lang.reflect.InaccessibleObjectException: Unable to make member of class
    // sun.security.ssl.SSLSocketFactoryImpl accessible:  module java.base does not export
    // sun.security.ssl to unnamed module @xxx
    throw UnsupportedOperationException(

But we want to be able to parameterize that fixed content.

## A "callable" instance { #a-callable-instance }

In Python there's a way to make an instance of a class a "callable".

Not the class itself (which is already a callable), but an instance of that class.

To do that, we declare a method `__call__`:

	wget -O /tmp/gopath/bin/docker-compose https://github.com/docker/compose/releases/download/${COMPOSE_VERSION}/docker-compose-linux-x86_64
	chmod +x /tmp/gopath/bin/docker-compose

	cleanup

	TAG=minio/minio:dev make docker

	MINIO_VERSION=RELEASE.2019-12-19T22-52-26Z docker-compose \
		-f "buildscripts/upgrade-tests/compose.yml" \
		up -d --build

	add_alias

	mc mb minio/minio-test/

func TestLoadOrStoreVisitMap(t *testing.T) {
	var vm visitMap
	var loaded bool
	type testM struct {
		Name string
	}

	t1 := testM{Name: "t1"}
	t2 := testM{Name: "t2"}
	t3 := testM{Name: "t3"}

	vm = make(visitMap)
	if loaded = loadOrStoreVisitMap(&vm, reflect.ValueOf(&t1)); loaded {
		t.Fatalf("loaded should be false")
	}

	if loaded = loadOrStoreVisitMap(&vm, reflect.ValueOf(&t1)); !loaded {

	// Map of LDAP user (internal representation) to list of active credential objects
	parentUserToCredsMap := make(map[string][]auth.Credentials)
	// DN to ldap username mapping for each LDAP user
	actualDNToLDAPUsernameMap := make(map[string]string)
	// External (actual) LDAP DN to internal normalized representation
	actualDNToParentUserMap := make(map[string]string)
	for _, cred := range allCreds {

		return fmt.Errorf("Unable to initialize sub-systems: %w", err)
	}
}

func initConfigSubsystem(ctx context.Context, newObject ObjectLayer) error {
	// %w is used by all error returns here to make sure
	// we wrap the underlying error, make sure when you
	// are modifying this code that you do so, if and when
	// you want to add extra context to your error. This
	// ensures top level retry works accordingly.

     * Given that we declare this method as accepting and returning non-nullable values (because we
     * implement Function<A, B>, as discussed in a class-level comment), it would make some sense to
     * perform runtime null checks on the input and output. (That would also make NullPointerTester
     * happy!) However, since we didn't do that for many years, we're not about to start now.