public function get_grouping_head()
    {
        if (!$this->is_single_grouping())
            throw new \Exception('Cannot use ' . __METHOD__ . ' here');
        foreach ($this->get_elements() as $record) {
            return $record;
        }
    }
public function get_grouping_head()
    {
        if (!$this->is_single_grouping())
            throw new \Exception('Cannot use ' . __METHOD__ . ' here');
        foreach ($this->get_elements() as $record) {
            return $record;
        }
    }
public function get_grouping_head ( ) { if ( ! $ this -> is_single_grouping ( ) ) throw new \ Exception ( 'Cannot use ' . __METHOD__ . ' here' ) ; foreach ( $ this -> get_elements ( ) as $ record ) { return $ record ; } }
When action on a single grouping, returns the image of himself

@return \record_adapter
When action on a single grouping returns the image of himself