code: protected String getBasicAuthRealmName(WebRequest webRequest) {
          SecurityMetadata securityMetadata = webRequest.getSecurityMetadata();
          if (securityMetadata != null) {
              LoginConfiguration loginConfig = securityMetadata.getLoginConfiguration();
              if (loginConfig != null && loginConfig.getRealmName() != null) {
                  return loginConfig.getRealmName();
              }
              if (config.getDisplayAuthenticationRealm()) {
                  return userRegistry.getRealm();
              }
          }
          String realm = "defaultRealm";
          return realm;
      }
docs: Return a realm name if it's defined in the web.xml file. If it's not defined in the web.xml
  and displayAuthenticationRealm is set to true, then return the userRegistry realm. Otherwise return
  the realm as "Default Realm".
  
  @param webRequest
  @return realm