Pagination with custom wp_query

pagination.php

// more options here: https://codex.wordpress.org/Function_Reference/paginate_links

public static function getPagination($pages = null)
{
    $args = array(
        'prev_next'     => false,
        'type'          => 'list'
    );

    if ($pages) {
        $args['total'] = $pages;
    }

    $html = paginate_links($args);
    return $html;
}

wp_query.php

$paged = get_query_var('paged') ? get_query_var('paged') : 1;

$args = array(
    'post_type'         => 'obra',
    'posts_per_page'    => get_option('posts_per_page'),
    'paged'             => $paged,
);

$posts = new \WP_Query($args);

$pages = $posts->max_num_pages;