public function readOnce($key)
    {
        $read = $this->get($key);
        $this->delete($key);
        return $read;
    }
public function readOnce($key)
    {
        $read = $this->get($key);
        $this->delete($key);
        return $read;
    }
public function readOnce ( $ key ) { $ read = $ this -> get ( $ key ) ; $ this -> delete ( $ key ) ; return $ read ; }
Read a value from the session and unset it, a form of read once flash
memory using the session.

@param string $key in session variable.

@return mixed value from session and null if not set.
Read a value from the session and unset it a form of read once flash memory using the session .