connect to microsoft exchange using EWS C#

using System;
using System.IO;
namespace Microsoft.Exchange.Samples.EWS
{
  class Tracing
  {
    private static TextWriter logFileWriter = null;
    public static void OpenLog(string fileName)
    {
      logFileWriter = new StreamWriter(fileName);
    }
    public static void Write(string format, params object[] args)
    {
      Console.Write(format, args);
      if (logFileWriter != null)
      {
        logFileWriter.Write(format, args);
      }
    }
    public static void WriteLine(string format, params object[] args)
    {
      Console.WriteLine(format, args);
      if (logFileWriter != null)
      {
        logFileWriter.WriteLine(format, args);
      }
    }
    public static void CloseLog()
    {
      logFileWriter.Flush();
      logFileWriter.Close();
    }
  }
}