title: Two urls with difference of one optional parameter to map to same resource in flask restful
body: <p>I have two endpoints:</p>
  
  <ul>
  <li><code>/api/v1/users</code></li>
  <li><code>/api/v1/&lt;resource&gt;/users</code></li>
  </ul>
  
  <p>I have a class that handles for the latter like this</p>
  
  <pre><code>class ListUsers(Resource):
      def post(self,resource):
           // get the list of users under that resource
  
  api.addResource(ListUsers,'/api/v1/&lt;resource&gt;/users')
  </code></pre>
  
  <p>If the <code>resource</code> is not specified, I want to list users from all resources. Is it possible to map both the urls to the same <code>class ListUsers</code> instead of writing another class for the first url?</p>