import com.google.common.util.concurrent.ClosingFuture.DeferredCloser;
import java.io.Closeable;
import java.util.concurrent.ExecutionException;
import org.jspecify.annotations.NullUnmarked;

/** Tests for {@link ClosingFuture} that exercise {@link ClosingFuture#finishToFuture()}. */
@NullUnmarked
public class ClosingFutureFinishToFutureTest extends AbstractClosingFutureTest {
  public void testFinishToFuture_throwsIfCalledTwice() throws Exception {

## 使用`jsonable_encoder`

让我们假设你有一个数据库名为`fake_db`，它只能接收与JSON兼容的数据。

例如，它不接收`datetime`这类的对象，因为这些对象与JSON不兼容。

因此，`datetime`对象必须将转换为包含<a href="https://en.wikipedia.org/wiki/ISO_8601" class="external-link" target="_blank">ISO格式化</a>的`str`类型对象。

同样，这个数据库也不会接收Pydantic模型（带有属性的对象），而只接收`dict`。

对此你可以使用`jsonable_encoder`。

它接收一个对象，比如Pydantic模型，并会返回一个JSON兼容的版本：

{* ../../docs_src/encoder/tutorial001_py310.py hl[4,21] *}

     * environment like {@link System#getProperties()} and environment variables.
     *
     * @return The system properties, never {@code null}.
     */
    Properties getSystemProperties();

    /**
     * Sets the system properties to use for interpolation. The system properties are collected from the runtime
     * environment like {@link System#getProperties()} and environment variables.
     *

## Ersetzendes Aktualisieren mit `PUT` { #update-replacing-with-put }

Um einen Artikel zu aktualisieren, können Sie die <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PUT" class="external-link" target="_blank">HTTP `PUT`</a> Operation verwenden.

    Map<K, V> map = new LinkedHashMap<>();
    for (Entry<K, V> entry : entries) {
      map.put(entry.getKey(), entry.getValue());
    }
    getMap().putAll(map);
  }

  /**
   * Returns the {@link Method} instance for {@link #testPutAll_nullKeyUnsupported()} so that tests
   * can suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="https://bugs.openjdk.org/browse/JDK-5045147">JDK-5045147</a> is fixed.

import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;
import org.jspecify.annotations.Nullable;

/**
 * Abstract test case parent for anything implementing {@link ListenableFuture}. Tests the two get
 * methods and the addListener method.
 *
 * @author Sven Mawson
 * @since 10.0
 */
@GwtIncompatible
public abstract class AbstractListenableFutureTest extends TestCase {

import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import org.jspecify.annotations.Nullable;

/**
 * Standard implementation of {@link ValueGraph} that supports the options supplied by {@link
 * AbstractGraphBuilder}.
 *
 * <p>This class maintains a map of nodes to {@link GraphConnections}.
 *
 * <p>Collection-returning accessors return unmodifiable views: the view returned will reflect

## Conclusión { #conclusion }

Con esto deberías tener una comprensión básica de qué son las **variables de entorno** y cómo usarlas en Python.

También puedes leer más sobre ellas en la <a href="https://en.wikipedia.org/wiki/Environment_variable" class="external-link" target="_blank">Wikipedia para Variable de Entorno</a>.

    * `Path()`
    * `Query()`
    * `Header()`
    * `Cookie()`

        for (Element h23element: h23elements) {
            String tag = h23element.tagName();
            String name = h23element.text();
            Element link = h23element.selectFirst("a");
            String anchor = (link != null) ? link.attr("id") : "";
            if(!name.startsWith("Table") && tag.equals("h2")){