public ReadOnlyCollection <Group> Get(long uid, bool extended = false, GroupsFilters filters = null, GroupsFields fields = null)
        {
            var parameters = new VkParameters {
                { "uid", uid }, { "extended", extended }, { "filter", filters }, { "fields", fields }
            };

            VkResponseArray response = _vk.Call("groups.get", parameters);

            if (!extended)
            {
                return(response.Select(id => new Group {
                    Id = id
                }).ToReadOnlyCollection());
            }

            // в первой записи количество членов группы
            return(response.Skip(1).ToReadOnlyCollectionOf <Group>(r => r));
        }