code: public String encrypt(String plainText) {
          Objects.requireNonNull(plainText, Required.PLAIN_TEXT.toString());
  
          return encrypt(plainText, getSizedSecret(this.config.getApplicationSecret()));
      }
docs: Encrypts a given plain text using the application secret property (application.secret) as key
  
  Encryption is done by using AES and CBC Cipher and a key length of 256 bit
  
  @param plainText The plain text to encrypt
  @return The encrypted text or null if encryption fails