docs: public String determinePrincipalIdFromAttributes(final String defaultId, final Map<String, List<Object>> attributes) {
          return FunctionUtils.doIf(
              StringUtils.isNotBlank(this.attribute) && attributes.containsKey(this.attribute),
              () -> {
                  val attributeValue = attributes.get(this.attribute);
                  LOGGER.debug("Using attribute [{}] to establish principal id", this.attribute);
                  return CollectionUtils.firstElement(attributeValue).get().toString();
              },
              () -> {
                  LOGGER.debug("Using principal id [{}] to generate persistent identifier", defaultId);
                  return defaultId;
              }
          ).get();
      }