public function addCustomerCustomerGroup(ChildCustomerCustomerGroup $l)
    {
        if ($this->collCustomerCustomerGroups === null) {
            $this->initCustomerCustomerGroups();
            $this->collCustomerCustomerGroupsPartial = true;
        }

        if (!in_array($l, $this->collCustomerCustomerGroups->getArrayCopy(), true)) { // only add it if the **same** object is not already associated
            $this->doAddCustomerCustomerGroup($l);
        }

        return $this;
    }