{* ../../docs_src/events/tutorial003.py hl[1,13] *}

Ein **Kontextmanager** in Python ist etwas, das Sie in einer `with`-Anweisung verwenden können, zum Beispiel kann `open()` als Kontextmanager verwendet werden:

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

In neueren Versionen von Python gibt es auch einen **asynchronen Kontextmanager**. Sie würden ihn mit `async with` verwenden:

```Python

@SuppressSignatureCheck
sealed class ConnectionEvent {
  abstract val timestampNs: Long
  open val connection: Connection?
    get() = null

  /** Returns if the event closes this event, or null if this is no open event. */
  open fun closes(event: ConnectionEvent): Boolean? = null

  val name: String
    get() = javaClass.simpleName

  data class ConnectStart(

for the Android flavor.

[Snapshot API Javadoc][guava-snapshot-api-docs] as well as
[Snapshot API Diffs][guava-snapshot-api-diffs] are also available.

Another easy way to get to the Javadoc is to open
[guava.dev/api](https://guava.dev/api). You can also jump right to a specific
class by appending the class name to guava.dev. For example,
[guava.dev/ImmutableList](https://guava.dev/ImmutableList)!

## Learn about Guava

    private long lastWriteTime;

    /**
     * Constructs an Open AndX response.
     *
     * @param config the configuration
     */
    public SmbComOpenAndXResponse(final Configuration config) {
        super(config);
    }

    /**
     * Constructs an Open AndX response with a chained response.
     *
     * @param config the configuration

          labels-to-remove-when-unstale: 'stat:awaiting response'
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          stale-issue-message: > 
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import java.net.ServerSocket
import javax.net.ServerSocketFactory

/**
 * A [ServerSocketFactory] that delegates calls. Sockets can be configured after creation by
 * overriding [.configureServerSocket].
 */
open class DelegatingServerSocketFactory(
  private val delegate: ServerSocketFactory,
) : ServerSocketFactory() {
  @Throws(IOException::class)
  override fun createServerSocket(): ServerSocket {

    } else {
      eventSequence.forEach loop@{
        when (e.closes(it)) {
          null -> return // no open event
          true -> return // found open event
          false -> return@loop // this is not the open event so continue
        }
      }
      Assertions.fail<Any>("event $e without matching start event")
    }
  }

  override fun connectStart(

    private static final Logger log = LoggerFactory.getLogger(SmbFileHandleImpl.class);

    private final Configuration cfg;
    private final int fid;
    private final byte[] fileId;
    private boolean open = true;
    private final long tree_num; // for checking whether the tree changed
    private SmbTreeHandleImpl tree;

    private final AtomicLong usageCount = new AtomicLong(1);
    private final int flags;

      for (int j = i + 1; j <= MAX_BOUND; j++) {
        for (BoundType lowerType : BoundType.values()) {
          for (BoundType upperType : BoundType.values()) {
            if (i == j & lowerType == OPEN & upperType == OPEN) {
              continue;
            }
            builder.add(Range.range(i, lowerType, j, upperType));
          }
        }
      }
    }
    RANGES = builder.build();
  }

📥, `shutdown` 🎉 🐕‍🦺 🔢 🔜 ✍ ✍ ⏸ `"Application shutdown"` 📁 `log.txt`.

/// info

`open()` 🔢, `mode="a"` ⛓ "🎻",, ⏸ 🔜 🚮 ⏮️ ⚫️❔ 🔛 👈 📁, 🍵 📁 ⏮️ 🎚.

///

/// tip

👀 👈 👉 💼 👥 ⚙️ 🐩 🐍 `open()` 🔢 👈 🔗 ⏮️ 📁.

, ⚫️ 🔌 👤/🅾 (🔢/🔢), 👈 🚚 "⌛" 👜 ✍ 💾.

✋️ `open()` 🚫 ⚙️ `async` & `await`.

, 👥 📣 🎉 🐕‍🦺 🔢 ⏮️ 🐩 `def` ↩️ `async def`.

///

/// info