public IReadOnlyCollection <Group> Get()
 {
     using (var vkApi = _vkApiFactory.Create())
     {
         return(vkApi
                .Groups
                .GetById(_groupNames, "", GroupsFields.MembersCount));
     }
 }
        public IReadOnlyCollection <Post> Get(long groupId, ulong offset)
        {
            using (var vkApi = _vkApiFactory.Create())
            {
                var res = vkApi.Wall.Get(new WallGetParams
                {
                    OwnerId = -groupId,
                    Offset  = offset,
                    Count   = 100
                });

                return(res.WallPosts);
            }
        }