docs: protected Map<String, String> initialize(final Map<String, Object> attributes) {
          val cachedAttributesToEncode = new HashMap<String, String>();
          removeAttributeAndCacheForEncoding(attributes, cachedAttributesToEncode, CasViewConstants.MODEL_ATTRIBUTE_NAME_PRINCIPAL_CREDENTIAL);
          removeAttributeAndCacheForEncoding(attributes, cachedAttributesToEncode, CasViewConstants.MODEL_ATTRIBUTE_NAME_PROXY_GRANTING_TICKET);
          removeAttributeAndCacheForEncoding(attributes, cachedAttributesToEncode, CasViewConstants.MODEL_ATTRIBUTE_NAME_PROXY_GRANTING_TICKET_IOU);
          return cachedAttributesToEncode;
      }