@Test
public void invalidConnectionPoolSize() {

    DockerClientConfig config = new DockerClientConfig(DockerCloudUtils.DOCKER_DEFAULT_SOCKET_URI,
            DockerAPIVersion.DEFAULT);
    assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(() -> config.connectionPoolSize(0));
    assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(() -> config.connectionPoolSize(-1));
}