public function init() {
        $opts = SettingsPage::getOptions();
        if ($opts[SettingsPage::ENABLE_ITEMCSV_OPT] === 'no') {
            return;
        }
        add_filter('usces_filter_downloadcsv_add_header', [get_class(), 'addHeaders']);
        add_filter('dlseller_filter_downloadcsv_add_header', [get_class(), 'addHeaders']);
        add_filter('usces_filter_downloadcsv_add_skuvalue', [get_class(), 'addComboSetCells'], 10, 2);
        add_filter('dlseller_filter_downloadcsv_add_skuvalue', [get_class(), 'addComboSetCells'], 10, 2);
        add_filter('usces_filter_uploadcsv_add_min_field_num', [get_class(), 'incrementUploadCSVFieldCount']);
        add_filter('dlseller_filter_uploadcsv_add_min_field_num', [get_class(), 'incrementUploadCSVFieldCount']);
        add_action('dlseller_after_uploadcsv_line_processed', [$this, 'prepareComboSet']);
        add_action('usces_after_uploadcsv_line_processed', [$this, 'prepareComboSet']);
        add_action('dlseller_after_uploadcsv_lines_processed', [$this, 'insertComboSets']);
        add_action('usces_after_uploadcsv_lines_processed', [$this, 'insertComboSets']);
    }