/// <summary>
 /// search repos
 /// http://developer.github.com/v3/search/#search-repositories
 /// </summary>
 /// <param name="search"></param>
 /// <returns>List of repositories</returns>
 public IObservable <SearchRepositoryResult> SearchRepo(SearchRepositoriesRequest search)
 {
     Ensure.ArgumentNotNull(search, nameof(search));
     return(_client.SearchRepo(search).ToObservable());
 }