/**
  * Gets the salt from the configuration and logs a warning if it's null.
  *
  * @return salt.
  */
 private static byte[] getSalt() {
   byte[] salt = null;
   if (configuration == null || ((salt = configuration.getObfuscationSalt()) == null)) {
     Log.w(LOG_TAG, "Can't (un)obfuscate purchases without salt");
   }
   return salt;
 }