Test for issue 1838 of ClosedXML

test1838.cs

using System;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.IO;
using ClosedXML.Excel;

namespace ConsoleApp11
{
    internal class Program
    {
        private static DataTable GetTable()
        {
            DataTable table = new DataTable();

            // add columns
            for (var col = 1; col <= 245; col++)
            {
                table.Columns.Add("col_" + col.ToString(), typeof(string));
            }

            List<string> valuesList = new List<String>();
            foreach (DataColumn dc in table.Columns)
            {
                valuesList.Add("testing 101.001000000000 test");
            }

            for (var row = 1; row <= 50000; row++)
            {
                table.Rows.Add(valuesList.ToArray());
            }

            return table;
        }

        public static void Main()
        {
            var table = GetTable();

            using (var workbook = new XLWorkbook())
            {
                var worksheet = workbook.Worksheets.Add("fgtesting");

                var stopwatch = Stopwatch.StartNew();

                worksheet.Cell(1, 1).InsertData(table);

                stopwatch.Stop();

                Console.WriteLine("Insert data {0}", stopwatch.Elapsed);

                using (var memoryStream = new MemoryStream())
                {
                    stopwatch.Restart();
                    workbook.SaveAs(memoryStream);
                    stopwatch.Stop();
                }

                Console.WriteLine("SaveAs to memory stream {0}", stopwatch.Elapsed);
            }
        }
    }
}