public ClientFactoryBuilder connectionPoolListener(
            ConnectionPoolListener connectionPoolListener, boolean autoClose) {
        option(ClientFactoryOptions.CONNECTION_POOL_LISTENER,
               requireNonNull(connectionPoolListener, "connectionPoolListener"));
        autoCloseConnectionPoolListener = autoClose;
        return this;
    }
Sets the listener which is notified on a connection pool event.

<p>If {@code autoClose} is true, {@link ConnectionPoolListener#close()} will be automatically called when
the {@link ClientFactory} is closed. Otherwise, you need to close it manually. {@code autoClose} is
enabled by default.
core/src/main/java/com/linecorp/armeria/client/ClientFactoryBuilder.java