Merge 2 query… Custom post and Category posts

Okay.. I found the solution.. with this query https://wordpress.stackexchange.com/questions/135820/merge-2-args-in-one-wp-query-and-order-it-by-date/179598#179598 but if you use sticky post.. do not forget to add ‘ignore_sticky_posts’ => 1.. and here is query with working example

<?php
// first query
$first_ids = get_posts( array(
    'fields'         => 'ids',
    'posts_per_page' => '6',
    'post_status'    => 'publish',
    'post_type'      => array('your_custom_post_type')
));

// second query
$second_ids = get_posts( array(
    'fields'         => 'ids',
    'posts_per_page' => '6',
    'post_status'    => 'publish',
    'post_type'      => 'post',
    'tax_query'      => array(array(
        'taxonomy'       => 'category',
        'field'          => 'term_id',
        'terms'          => array(7) // your category ID
    ))
));

// merging ids
$post_ids = array_merge( $first_ids, $second_ids);

// the main query
$query = new WP_Query(array(
    'post_type' => 'any',
    'post__in'  => $post_ids,
    'orderby'   => 'date',
    'order'     => 'DESC',
    'ignore_sticky_posts' => 1
));

if ( $query->have_posts() ) : while ( $query->have_posts() ) : $query->the_post();
echo the_title().'<br>';
endwhile; endif;
?>