code: @Nullable
      public byte[] getCipherKey() {
          Object cipherKey = getSetting(CIPHER_KEY);
          if (cipherKey instanceof String) {
              cipherKey = KryptKt.toBinaryKey((String) cipherKey);
              setSetting(CIPHER_KEY, cipherKey);
          }
          return (byte[]) cipherKey;
      }
docs: Returns the key which will be used to encrypt the database or {@code null} for no encryption. Is applicable
  only if* {@linkplain #getCipherId()} returns not {@code null}. Default value is {@code null}.
  <p>Mutable at runtime: no
  
  @return the key which will be used to encrypt the database or {@code null} for no encryption
  @see #getCipherId()
  @see #getCipherBasicIV()
  @see StreamCipher
  @see StreamCipher#init(byte[], long)
  @see StreamCipherProvider