@Deprecated public boolean isSessionValid(){
  return (getAccessToken() != null) && ((getAccessExpires() == 0) || (System.currentTimeMillis() < getAccessExpires()));
}

@ Deprecated public boolean isSessionValid ( ) { return ( getAccessToken ( ) != null ) && ( ( getAccessExpires ( ) == 0 ) || ( System . currentTimeMillis ( ) < getAccessExpires ( ) ) ) ; }
returns whether the current access token is valid
