title: Decorating GET method with api.expect() Flask-RESTPlus
body: <p>I have an endpoint that I decorated with <code>api.expect()</code>, but I am getting this error. </p>
  
  <pre><code>{
      "message": "Input payload validation failed",
      "errors": {
          "": "None is not of type u'object'"
      }
  }
  </code></pre>
  
  <p>This is what my code looks like for simplicity.</p>
  
  <pre><code>@api.route('/history')
  class ProfitAnalyticsResource(Resource):
  
      method_decorators = [jwt_required]
  
      @api.expect(api.model('HistoryParameters', {
          'jobId': fields.Integer(required=True, description='Job ID')
      }), validate=True)
      def get(self):
          """ Gets the profit analytics report for the current user"""
  
          return "test only"
  </code></pre>
  
  <p>I am testing this on Postman, passing in <code>jobId</code> as a url parameter.</p>