title: Cannot find reference 'Counter' in 'compat.py'
body: <p>I am trying to run nltk's BLEU score calculation module that I got from <a href="http://www.nltk.org/_modules/nltk/align/bleu.html" rel="nofollow noreferrer">here</a>. But am getting an error for the following import.</p>
  
  <pre><code>from nltk.compat import Counter
  </code></pre>
  
  <p>I tried a pip install of the Counter and it has been successfully installed. I have used the same interpreter for this project. But this is still shown as an error.</p>
  
  <blockquote>
    <p>Cannot find reference 'Counter' in 'compat.py'</p>
  </blockquote>
  
  <p>I'm using Python 3.5 and working in pycharm. </p>
  
  <p><a href="https://i.stack.imgur.com/HoN7J.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HoN7J.png" alt="enter image description here"></a></p>
  
  <p>Any suggestions in getting this resolved will be highly appreciated.</p>