code: public String decrypt(String text, PrivateKey key) throws MangooEncryptionException {
          Objects.requireNonNull(text, Required.ENCRYPTED_TEXT.toString());
          Objects.requireNonNull(text, Required.PRIVATE_KEY.toString());
          
          String decrypt = null;
          try {
              byte[] dectyptedText = decrypt(decodeBase64(text), key);
              decrypt = new String(dectyptedText, StandardCharsets.UTF_8);
          } catch (MangooEncryptionException e) {
              throw new MangooEncryptionException("Failed to decrypt encrypted text with private key", e);
          }
  
          return decrypt;
      }
docs: Decrypt Base64 encoded text using private key
  
  @param text The encrypted text, encoded as Base64
  @param key The private key
  
  @return The plain text encoded as UTF8
  @throws MangooEncryptionException if decryption fails