code: @Override
      public Account verify(String id, Credential credential) {
          if (id == null || id.length() == 0) {
              HttpServerLogger.ROOT_LOGGER.debug("Missing or empty username received, aborting account verification.");
              return null;
          }
  
          if (credential instanceof PasswordCredential) {
              return verify(id, (PasswordCredential) credential);
          } else if (credential instanceof DigestCredential) {
              return verify(id, (DigestCredential) credential);
          }
  
          throw HttpServerLogger.ROOT_LOGGER.invalidCredentialType(credential.getClass().getName());
      }
docs: /*
  This verify method is used to verify both BASIC authentication and DIGEST authentication requests.