title: Normalizr and recursive nested structure
body: <p>I'm using normalizr to flatten a structure like the following one:</p>
  
  <pre><code>{
    "fields":[{
      "id":"29",
      "text": "something"
    }, {
      "id":"16",
      "text": "something"
      "fields":[{
        "id":"17",
        "text": "something"
      }]
    }, {
      "id":"18",
      "text": "something"
    }
  }
  </code></pre>
  
  <p>My structure has an array of <strong>fields</strong> and a <strong>field</strong> may also have nested fields. There's only <strong>one level of nesting allowed</strong>.</p>
  
  <p>What I'm trying to do is this:</p>
  
  <pre><code>const block = new schema.Entity('fields')
  const blockList = new schema.Array(block)
  
  block.define({
    fields: blockList
  })
  
  const normalizedData = normalize(originalData, blockList)
  </code></pre>
  
  <p>After running this snippet, normalizedData has a <strong>results</strong> property and it only has the first level of field ids, even though <strong>entities</strong> has all the fields normalized, including the nested ones.</p>
  
  <p><a href="https://i.stack.imgur.com/A32sH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/A32sH.png" alt="result of normalize"></a></p>
  
  <p>I'd like to have in the <strong>results</strong> array all the ids, including the nested ones. What am I missing?</p>