private Optional<String> getSetting(final String name) {
        return Optional.ofNullable(TestcontainersConfiguration.getInstance().getEnvVarOrUserProperty(name, null));
    }
Use environment variables and system properties (as supported by the underlying DockerClient DefaultConfigBuilder)
to try and locate a docker environment.
<p>
Resolution order is:
<ol>
    <li>DOCKER_HOST env var</li>
    <li>docker.host in ~/.testcontainers.properties</li>
</ol>

@deprecated this class is used by the SPI and should not be used directly
core/src/main/java/org/testcontainers/dockerclient/EnvironmentAndSystemPropertyClientProviderStrategy.java