public IEnumerable <Document> ReadDocuments(
DocumentReader documentReader,
HashSet <string> select,
int skip = 0,
int take = 0)
{
var docCount = documentReader.DocumentCount();
if (take == 0)
{
take = docCount;
}
var took = 0;
long docId = skip;
while (docId <= docCount && took++ < take)
{
yield return(ReadDocument((documentReader.CollectionId, docId++), select, documentReader));
}
}