Entity/Menu.php
public function removeChild(\Skillberto\SonataPageMenuBundle\Entity\Menu $children)
    {
        $this->children->removeElement($children);
    }
public function removeChild(\Skillberto\SonataPageMenuBundle\Entity\Menu $children)
    {
        $this->children->removeElement($children);
    }
Remove children

@param \Skillberto\SonataPageMenuBundle\Entity\Menu $children