private IEnumerable <object> ExecuteBulkCopy(IEnumerable <TInput> input, SqlConnection conn)
        {
            var reader = new ObjectDataReader <TInput>(input);

            using (var bcp = new SqlBulkCopy(conn))
            {
                bcp.DestinationTableName = _destinationTable;
                bcp.BulkCopyTimeout      = (int)Math.Ceiling(Timeout.TotalSeconds);
                SetupMappings(bcp);
                bcp.Insert(reader);
            }
            return(Enumerable.Empty <object>());
        }