Export/Formatter/CSVFormatter.php
protected function orderingHeaders($formatterData)
    {
        $this->formatterData = $formatterData;
        uasort($this->formatterData, function($a, $b) {
            
            return ($a['order'] <= $b['order'] ? -1 : 1);
        });
    }
protected function orderingHeaders($formatterData)
    {
        $this->formatterData = $formatterData;
        uasort($this->formatterData, function($a, $b) {
            
            return ($a['order'] <= $b['order'] ? -1 : 1);
        });
    }
protected function orderingHeaders ( $ formatterData ) { $ this -> formatterData = $ formatterData ; uasort ( $ this -> formatterData , function ( $ a , $ b ) { return ( $ a [ 'order' ] <= $ b [ 'order' ] ? - 1 : 1 ) ; } ) ; }
ordering aggregators, preserving key association.

This function do not mind about position.

If two aggregators have the same order, the second given will be placed
after.  This is not significant for the first ordering.

@param type $formatterData
@return type
ordering aggregators preserving key association .