A minimal example about WordPress object cache

function wp_object_cache_sample_function() {
    $key = "your_cache_key";
    if ( ! $query = wp_cache_get($key) ) {
        $args = array(  
            'post_type' => 'services',
            'post_status' => 'publish',
            'posts_per_page' => 8, 
            'orderby’ => 'title', 
            'order’ => 'ASC', 
        );

        $query = new WP_Query($args);
        wp_cache_set($key,$query,'',3600);
    }
    return $query;
}