title: CakePHP tree behaviour not working
body: <p>I am learning cakePHP 3 and trying to store hierarchical data in a table. I have added parent_id, lft and rght columns. Added $this->addBehavior('Tree') in initialize method for this table. Calling recover method.</p>
  
  <p>So seems all is done as described here: <a href="https://book.cakephp.org/3.0/en/orm/behaviors/tree.html" rel="nofollow noreferrer">https://book.cakephp.org/3.0/en/orm/behaviors/tree.html</a>
  But no one child row is returned. </p>
  
  <p>I am newbie in cakePHP, so maybe someone can help, what I am doing wrong?</p>
  
  <p>That is interesting, that childCount returns -0.5 for each row (no matter if the row has children or not).</p>