public function getTopKeyWordsWithoutHits(int $rootPageId, int $days = 30, int $limit = 10) : array
    {
        return $this->getTopKeyWordsWithOrWithoutHits($rootPageId, $days, $limit, true);
    }
public function getTopKeyWordsWithoutHits(int $rootPageId, int $days = 30, int $limit = 10) : array
    {
        return $this->getTopKeyWordsWithOrWithoutHits($rootPageId, $days, $limit, true);
    }
public function getTopKeyWordsWithoutHits ( int $ rootPageId , int $ days = 30 , int $ limit = 10 ) : array { return $ this -> getTopKeyWordsWithOrWithoutHits ( $ rootPageId , $ days , $ limit , true ) ; }
Find Top search keywords without results

@param int $rootPageId
@param int $days number of days of history to query
@param int $limit
@return array
Find Top search keywords without results