title: Parsing a list of integers in flask-restful
body: <p>I'm using the <a href="http://flask-restful.readthedocs.org/" rel="noreferrer">flask-restful</a>, and I'm having trouble constructing a <code>RequestParser</code> that will validate a list of only integers.  Assuming an expected JSON resource format of the form:</p>
  
  <pre><code>{
      'integer_list': [1,3,12,5,22,11, ...] # with a dynamic length
  }
  </code></pre>
  
  <p>... and one would then create a RequestParser using a form something like:</p>
  
  <pre><code>from flask.ext.restful import reqparse
  parser = reqparse.RequestParser()
  parser.add_argument('integer_list', type=list, location='json')
  </code></pre>
  
  <p>... but how can i validate is an integer list?</p>