docs: public static SecretKey newSecretKey() {
  
          // FYI: AES keys are just random bytes from a strong source of randomness.
  
          // Get a key generator instance
          KeyGenerator keyGenerator;
          try {
              keyGenerator = KeyGenerator.getInstance(SYMMETRIC_ALGORITHM);
          } catch (NoSuchAlgorithmException e) {
              try {
                  if (SecurityProvider.addProvider()) {
                      keyGenerator = KeyGenerator.getInstance(SYMMETRIC_ALGORITHM);
                  } else keyGenerator = null;
              } catch (NoSuchAlgorithmException e1) {
                  keyGenerator = null;
              }
              if (keyGenerator == null) {
                  throw new IllegalStateException("Algorithm unavailable: " + SYMMETRIC_ALGORITHM, e);
              }
          }
  
          // Generate a key:
          keyGenerator.init(SYMMETRIC_KEY_SIZE);
          return keyGenerator.generateKey();
      }