WordPress gallery cache

Sorry Here`s the code, Thanx in advanced.

<?php
$args = array(
    'post_parent'    => $post->ID,
    'post_type'      => 'attachment',
    'post_mime_type' => 'image',
    'order'          => 'ASC',
    'orderby'        => 'menu_order',
    'numberposts'    => 4,
    'post_status'    => null,
);

$attachments = get_children($args);

if ( $attachments ) :

    foreach ( $attachments as $attachment ) :

    ?>

    <div class="uk-width-small-1-2 uk-width-medium-1-4 id-<?php echo $post->ID; ?>">
        <a href="<?php echo $attachment->guid; ?>" data-uk-lightbox="{group:'post-id-<?php echo $post->ID; ?>'}">
            <?php echo wp_get_attachment_image( $attachment->ID, 'small-thumbnail', false );; ?>
        </a>
    </div>

    <?php

    endforeach;

endif;
?>