Pimcore\Model\Object\ClassDefinition\Data\Fieldcollections::save PHP Method

    public function save($object, $params = [])
    {
        $container = $this->getDataFromObjectParam($object);
        if ($container instanceof Object\Fieldcollection) {
            $params = ["context" => ["containerType" => "fieldcollection", "fieldname" => $this->getName()]];
            $container->save($object, $params);
        }
    }