docs: public static String getMimeTypeForFileName(String fileName) {
  		int extensionPos = fileName.lastIndexOf('.');
  		if (extensionPos >= 1 && extensionPos < fileName.length() - 1) {
  			String extension = fileName.substring(extensionPos + 1);
  			return getMimeTypeForExtension(extension);
  		}
  		else {
  			return null;
  		}
  	}