public static StaticInitializer staticInitializer() {
        return new StaticInitializer();
    }
Represents a pre-defined set of self-contained JAR file resources in the Embulk JAR file.

<p>{@link org.embulk.EmbulkDependencyClassLoader} is introduced only to control the visibility from plugins,
not for customizability. It is intentionally designed to be a singleton.
embulk-core/src/main/java/org/embulk/cli/SelfContainedJarFiles.java