private static IReadOnlyList <DocumentId> ReadFirstDocumentIdInBlock(ref Utf8JsonStreamReader reader) { var firstDocumentIdInBlock = new List <DocumentId>(); H.ReadToken(ref reader, JsonTokenType.StartArray); while (reader.Read() && reader.TokenType != JsonTokenType.EndArray) { firstDocumentIdInBlock.Add(new DocumentId(reader.GetUInt32())); } return(firstDocumentIdInBlock); }