That converts the function into something called an "**async context manager**".

{* ../../docs_src/events/tutorial003_py39.py hl[1,13] *}

A **context manager** in Python is something that you can use in a `with` statement, for example, `open()` can be used as a context manager:

```Python
with open("file.txt") as file:
    file.read()
```

		t.Fatalf("unexpected error: %v", err)
	}
	if err := ps.Subscribe(MaskAll, ch2, doneCh2, nil); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	close(doneCh1)
	// Allow for the above statement to take effect.
	time.Sleep(100 * time.Millisecond)
	ps.Lock()
	if len(ps.subs) != 1 {
		t.Fatal("expected 1 subscriber")
	}
	ps.Unlock()
	close(doneCh2)
}

type maskString string

# Import compat before trying to import summary from tensorboard, so that
# reexport_tf_summary can get compat from sys.modules. Only needed if using
# lazy loading.
_current_module.compat.v2  # pylint: disable=pointless-statement

# Load tensorflow-io-gcs-filesystem if enabled
if (_os.getenv("TF_USE_MODULAR_FILESYSTEM", "0") == "true" or
    _os.getenv("TF_USE_MODULAR_FILESYSTEM", "0") == "1"):

Eso convierte a la función en algo llamado un "**async context manager**".

{* ../../docs_src/events/tutorial003_py39.py hl[1,13] *}

Un **context manager** en Python es algo que puedes usar en un statement `with`, por ejemplo, `open()` puede ser usado como un context manager:

```Python
with open("file.txt") as file:
    file.read()
```

		t.Errorf("Failed, got error: %v", err)
	}
}

func TestGaussDBOnConstraint(t *testing.T) {
	t.Skipf("This test case skipped, because of gaussdb not support 'ON CONSTRAINT' statement")
	if DB.Dialector.Name() != "gaussdb" {
		t.Skip()
	}

	type Thing struct {
		gorm.Model
		SomeID  string
		OtherID string
		Data    string
	}

	DB.Migrator().DropTable(&Thing{})

          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or

 * {@linkplain #close closed}. This was intended to approximately emulate the behavior of Java 7's
 * <a href="http://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html"
 * >try-with-resources</a> statement in JDK6-compatible code. Code using this should be
 * approximately equivalent in behavior to the same code written with try-with-resources.
 *
 * <p>This class is intended to be used in the following pattern:
 *

	// we need to do this so that the user has a policy before authentication.
	// ldap user accounts without policies are denied access in sftp.
	policy := "mypolicy"
	policyBytes := []byte(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject",
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::BUCKET/*"
   ]
  }
 ]
}`)

 * ({@code [ ]}) indicates that the range is closed on that side; a parenthesis ({@code ( )}) means
 * it is either open or unbounded. The construct {@code {x | statement}} is read "the set of all
 * <i>x</i> such that <i>statement</i>.")
 *
 * <blockquote>
 *
 * <table>
 * <caption>Range Types</caption>
 * <tr><th>Notation        <th>Definition               <th>Factory method

	})

	if !regexp.MustCompile(`INSERT INTO .pets. \(.name.,.user_id.\) .*VALUES \(.+,\(SELECT @uid:=id FROM \(SELECT id FROM .users. WHERE name=.+\) as tmp\)\),\(.+,@uid\)`).MatchString(result.Statement.SQL.String()) {
		t.Errorf("invalid insert SQL, got %v", result.Statement.SQL.String())
	}
}

func TestCreateNilPointer(t *testing.T) {
	var user *User

	err := DB.Create(user).Error
	if err == nil || err != gorm.ErrInvalidValue {