in src/main/java/org/apache/sling/commons/logservice/internal/SLF4JSupport.java [81:105]
    private String getLoggerName(final Bundle bundle) {
        String name;
        if (bundle == null) {
            // if we have no bundle, use the system bundle's name
            name = Constants.SYSTEM_BUNDLE_SYMBOLICNAME;
        } else {
            // otherwise use the bundle symbolic name
            name = bundle.getSymbolicName();
            // if the bundle has no symbolic name, use the location
            if (name == null) {
                name = bundle.getLocation();
            }
            // if the bundle also has no location, use the bundle Id
            if (name == null) {
                name = String.valueOf(bundle.getBundleId());
            }
        }
        return name;
    }