title: How to combine document list to corpus
body: <p>I can't combine many lists into 1 document
  example of my documents like this</p>
  
  <p><code>['universitas', 'trunojoyo']
   ['trunojoyo', 'ada', 'diklat', 'bumi']
   ['roadshow', 'speedy', 'trunojoyo', 'isi']</code></p>
  
  <p>I tried it with this code but it made the tearm break apart</p>
  
  <p><code>' '.join(str(x)for x in documents)
   ' '.join(map(str, documents))</code> </p>
  
  <p>and I want the results like this</p>
  
  <p><code>['universitas trunojoyo', 'trunojoyo ada diklat bumi', 'roadshow speedy trunojoyo isi']</code> </p>