getPreviouslyAttached() in AbstractSourceJarMojo is unused dead code

[elharo]

AbstractSourceJarMojo.java:330-336 contains a private method getPreviouslyAttached() that is never called anywhere in the codebase:

private Artifact getPreviouslyAttached(Artifact artifact, Project checkProject, String classifier) {
    return artifact.getExtension().equals(getExtension())
                    && artifact.getGroupId().equals(checkProject.getGroupId())
                    && artifact.getArtifactId().equals(checkProject.getArtifactId())
                    && artifact.getVersion().toString().equals(checkProject.getVersion())
                    && Objects.equals(artifact.getClassifier(), classifier)
            ? artifact
            : null;
}

This is dead code and should be removed to avoid confusion.