title: Postgres function WITH in Laravel QueryBuilder
body: <p>please help me.</p>
  
  <p>I've got the raw SQL </p>
  
  <pre><code>WITH collections AS (
      SELECT 
          ...
      FROM
          ...
  )
  SELECT
      ...
  FROM collections c1
  LEFT JOIN collections c2
      ...
  </code></pre>
  
  <p>How I can write it using Laravel QueryBuilder?</p>