public function buildAddressOptions() {
    $address_formatter = new ACMAddressFormatter();
    $user = $this->getCurrentCommerceUser();
    $addresses = $user->getAddresses();

    // Stored addresses.
    foreach ($addresses as $address) {
      $option_id = $address['address_id'];
      $options[$option_id] = [
        'id' => $option_id,
        'label' => $address_formatter->render((object) $address),
      ];
    }

    // New address.
    $option_id = 'new_address';
    $options[$option_id] = [
      'id' => $option_id,
      'label' => $this->t('New address'),
    ];

    return $options;
  }