code: private WebAuthenticator getAuthenticatorForFailOver(String authType, WebRequest webRequest) {
          WebAuthenticator authenticator = null;
          if (LoginConfiguration.FORM.equals(authType)) {
              authenticator = createFormLoginAuthenticator(webRequest);
          } else if (LoginConfiguration.BASIC.equals(authType)) {
              authenticator = getBasicAuthAuthenticator();
          }
          return authenticator;
      }
docs: Get the appropriate Authenticator based on the authType
  
  @param authType the auth type, either FORM or BASIC
  @param the WebRequest
  @return The WebAuthenticator or {@code null} if the authType is unknown