code: function retrieveAssociation(req, res) {
    if(redirect(req.params.id, '', '', res)) {
      return;
    }
  
    switch(req.accepts(['json', 'html'])) {
      // TODO: support HTML in future
      //case 'html':
      //  res.sendFile(path.resolve(__dirname + '/../../web/association.html'));
      //  break;
      default:
        var id = req.params.id;
        var rootUrl = req.protocol + '://' + req.get('host');
        var queryPath = req.originalUrl;
        req.chickadee.getAssociation(req, id, null, rootUrl, queryPath,
                                     function(response, status) {
          res.status(status).json(response);
        });
        break;
    }
  }
docs: Retrieve the given association.
  @param {Object} req The HTTP request.
  @param {Object} res The HTTP result.