* the event source has already been closed or canceled.
   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new event source and immediately returns it. Creating an event source initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must cancel the returned event source when it is no longer in use.
     */

- **Resource management** - Proper handling of resources with utilities like `CloseableUtil` and `DisposableUtil`

### Key Architectural Patterns
- **Factory Pattern** - `BeanDescFactory` for creating bean descriptors, `ParameterizedClassDescFactory` for generic type handling
- **Builder Pattern** - `CopyOptions` for configuring bean copying operations with fluent API

   * symmetry. Moreover, we don't want to reconstruct a native type variable {@code <A>} using our
   * implementation unless some of its bounds have changed in resolution. This avoids creating
   * unequal TypeVariable implementation unnecessarily. When the bounds do change, however, it's
   * fine for the synthetic TypeVariable to be unequal to any native TypeVariable anyway.
   */

 * limitations under the License.
 */

package com.google.common.collect.testing;

import static com.google.common.collect.testing.testers.ListListIteratorTester.getListIteratorFullyModifiableMethod;
import static com.google.common.collect.testing.testers.ListSubListTester.getSubListOriginalListSetAffectsSubListLargeListMethod;
import static com.google.common.collect.testing.testers.ListSubListTester.getSubListOriginalListSetAffectsSubListMethod;

   * symmetry. Moreover, we don't want to reconstruct a native type variable {@code <A>} using our
   * implementation unless some of its bounds have changed in resolution. This avoids creating
   * unequal TypeVariable implementation unnecessarily. When the bounds do change, however, it's
   * fine for the synthetic TypeVariable to be unequal to any native TypeVariable anyway.
   */

          <show>package</show>
        </configuration>
      </plugin>
      <!-- Disable "normal" testing, which doesn't work for GWT tests. -->
      <plugin>
        <artifactId>maven-surefire-plugin</artifactId>
        <configuration>
          <skip>true</skip>
        </configuration>
      </plugin>

   *
   * No further calls to this listener will be made.
   */
  open fun onClosed(eventSource: EventSource) {
  }

  /**
   * Invoked when an event source has been closed due to an error reading from or writing to the
   * network. Incoming events may have been lost. No further calls to this listener will be made.
   */
  open fun onFailure(
    eventSource: EventSource,
    t: Throwable?,

import mockwebserver3.junit5.StartStop
import okhttp3.Headers
import okhttp3.OkHttpClientTestRule
import okhttp3.Request
import okhttp3.sse.EventSource.Companion.processEventSource
import okhttp3.testing.PlatformRule
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.Tag
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.RegisterExtension

@Tag("Slowish")

import okhttp3.OkHttpClientTestRule
import okhttp3.RecordingEventListener
import okhttp3.Request
import okhttp3.sse.EventSource
import okhttp3.sse.EventSource.Factory.Companion.asEventSourceFactory
import okhttp3.testing.PlatformRule
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.Tag
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.RegisterExtension
import org.junitpioneer.jupiter.RetryingTest

          if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

          System.out.println(response.body().string());
        }
      }
    ```

### Post Streaming ([.kt][PostStreamingKotlin], [.java][PostStreamingJava])