docs: public static final String extractPackageName(String className) {
  		if (className == null || className.trim().isEmpty()) {
  			return "";
  		}
  		
  		final int idx = className.lastIndexOf('.');
  		if (idx == -1) {
  			return "";
  		} else {
  			return className.substring(0, idx);
  		}
  	}