code: function(conversationId, params, callback) {
        conversationId = utils.toUUID(conversationId);
        if (!conversationId) return callback(new Error(utils.i18n.messages.cid));
        utils.debug('Message getAll: ' + conversationId);
  
        var queryParams = '';
        if (typeof params === 'function') callback = params;
        else queryParams = '?' + querystring.stringify(params);
  
        request.get({
          path: '/conversations/' + conversationId + '/messages' + queryParams
        }, callback);
      }
docs: Retrieve messages in a conversation
  
  @param  {String}   conversationId  Conversation ID
  @param  {String}   [params]        Query parameters
  @param  {Function} callback        Callback function