.build()
    val call = client.newCall(request)
    call.enqueue(callback)
    val recordedResponse = callback.await(server.url("/"))
    assertThat(recordedResponse.failure, "canceled due to java.lang.RuntimeException: boom!")
    recordedResponse.failure!!.assertSuppressed { throwables: List<Throwable>? ->
      assertThat(throwables!!).contains(boom)
      Unit
    }
    assertThat(call.isCanceled()).isTrue()

            logger
                .get()
                .log(
                    Level.WARNING,
                    "Error while attempting to shut down the service after failure.",
                    ignored);
          }
          notifyFailed(t);
          // requireNonNull is safe now, just as it was above.
          requireNonNull(runningTask).cancel(false); // prevent future invocations.

    } catch (AssertionFailedError expected) {
      for (String message : expectedMessages) {
        assertThat(expected).hasMessageThat().contains(message);
      }
      return;
    }
    fail("expected failure not reported");
  }

  private class ForwardingRunnable implements Runnable {

    private final Runnable runnable;

    ForwardingRunnable(Runnable runnable) {
      this.runnable = runnable;
    }

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class CollectionRetainAllTester<E> extends AbstractCollectionTester<E> {

  /** A collection of elements to retain, along with a description for use in failure messages. */
  private final class Target {
    private final Collection<E> toRetain;
    private final String description;

    private Target(Collection<E> toRetain, String description) {
      this.toRetain = toRetain;

    public ChannelInfo selectChannel(CommonServerMessageBlock message) {
        return loadBalancer.selectChannel(message);
    }

    /**
     * Handle channel failure
     *
     * @param channel failed channel
     * @param error error that caused failure
     */
    public void handleChannelFailure(ChannelInfo channel, Exception error) {
        failover.handleFailure(channel, error);
    }

    /**

        assertThrows(SmbException.class, () -> tree.treeConnect(null, null));
        // After failure, state should be reset to disconnected
        assertEquals(0, tree.connectionState);
    }

    @Test
    void testSend() throws SmbException {
        SmbTree tree = new SmbTree(session, "testShare", "A:");

 *     .build();
 * client.newCall(request).execute();
 * ```
 *
 * As expected, this fails with a certificate pinning exception:
 *
 * ```java
 * javax.net.ssl.SSLPeerUnverifiedException: Certificate pinning failure!
 * Peer certificate chain:
 *     sha256/afwiKY3RxoMmLkuRW1l7QsPZTJPwDS2pdDROQjXw8ig=: CN=publicobject.com, OU=PositiveSSL
 *     sha256/klO23nT2ehFDXCfx3eHTDRESMz3asj1muO+4aIdjiuY=: CN=COMODO RSA Secure Server CA

            } else if (!artifact.getFile().exists()) {
                String error = updateCheckManager.getError(artifact, repository);
                if (error != null) {
                    throw new TransferFailedException("Failure to resolve " + remotePath + " from "
                            + repository.getUrl()
                            + " was cached in the local repository. "

                 * junk. We need to bump up the wordCount here so that this method returns
                 * the correct number of bytes for signing purposes. Otherwise we get a
                 * signing verification failure.
                 */
                if (command == SMB_COM_NT_CREATE_ANDX && ((SmbComNTCreateAndXResponse) this).isExtended) {
                    wordCount += 8;
                }
            }

        // Act & Assert
        assertThrows(NullPointerException.class, () -> handler.openConnection(null), "Null URL should throw NPE");
        verify(mockCtx, never()).getConfig(); // no interaction expected on failure before construction
    }

    @Test
    @DisplayName("openConnection uses SingletonContext when no context provided")
    void testOpenConnection_UsesSingletonContext() throws Exception {
        // Arrange