private boolean tokenClientExists(String clientId,String relam,Context context){
  try {
    clientRegistrationStore.get(clientId,relam,context);
  }
 catch (  InvalidClientException|NotFoundException e) {
    return false;
  }
  return true;
}

private boolean tokenClientExists ( String clientId , String relam , Context context ) { try { clientRegistrationStore . get ( clientId , relam , context ) ; } catch ( InvalidClientException | NotFoundException e ) { return false ; } return true ; }
checks if the client to which the access token is issued exists
