code: public void initFromFile(final String filename) {
  		try (final InputStream is = new FileInputStream(filename)) {
  			init(is);
  		} catch (IOException e) {
  			initBackToDefaults();
  		}
  	}
docs: Init with a given filename. This is usually called from ServletContextListener with
  sce.getServletContext().getRealPath("/META-INF/MANIFEST.MF")
  
  @param filename
  to read the Manifest file from