code: @Override
      public Object sanitizeKey(Object cacheKey) throws KeySanitationExcepion {
          if (!(cacheKey instanceof String)) {
              throw new KeySanitationExcepion(DefaultKeySanitizer.class.getSimpleName() + " can only be used with Strings cache keys.");
          }
          try {
              return Base64.encodeToString(((String) cacheKey).getBytes(UTF8_CHARSET_NAME), BASE64_FLAGS);
          } catch (UnsupportedEncodingException e) {
              throw new KeySanitationExcepion(e);
          }
      }
docs: ----------------------------------