public static function add($productID, $data)
 {
     $variation = new self();
     $variation->setProductID($productID);
     $variation->setVariationSKU($data['pvSKU']);
     $variation->setVariationPrice($data['pvPrice']);
     $variation->setVariationSalePrice($data['pvSalePrice']);
     $variation->setVariationQty($data['pvQty']);
     $variation->setVariationQtyUnlim($data['pvQtyUnlim']);
     $variation->setVariationFID($data['pvfID']);
     $variation->setVariationWeight($data['pvWidth']);
     $variation->setVariationNumberItems($data['pvNumberItems']);
     $variation->setVariationHeight($data['pvHeight']);
     $variation->setVariationLength($data['pvLength']);
     $variation->setVariationWidth($data['pvWeight']);
     $variation->save();
     return $variation;
 }