public function addPicture(ChildPicture $l)
    {
        if ($this->collPictures === null) {
            $this->initPictures();
            $this->collPicturesPartial = true;
        }

        if (!$this->collPictures->contains($l)) {
            $this->doAddPicture($l);
        }

        return $this;
    }