public String getImagePullPolicy() {
        return getEnvVarOrProperty("pull.policy", null);
    }
Provides a mechanism for fetching configuration/default settings.
<p>
Configuration may be provided in:
<ul>
    <li>A file in the user's home directory named <code>.testcontainers.properties</code></li>
    <li>A file in the classpath named <code>testcontainers.properties</code></li>
    <li>Environment variables</li>
</ul>
<p>
Note that, if using environment variables, property names are in upper case separated by underscores, preceded by
<code>TESTCONTAINERS_</code>.
core/src/main/java/org/testcontainers/utility/TestcontainersConfiguration.java