Add entity collection to anemic model

    /**
     * Populate organisation with given already existing user list.
     *
     * @param array $userList
     *
     * @return \Doctrine\Common\Collections\ArrayCollection
     */
    private function populateUsers(array $userList): ArrayCollection
    {
        $collection = new ArrayCollection();

        foreach ($userList as $userId) {
            if ($collection->contains($userId)) {
                continue;
            }

            $user = $this->userRepository->find($userId);
            if ($user) {
                $collection[] = $user;
            }
        }

        return $collection;
    }