/// <summary>
 /// Inherited code: Requires comment.
 /// </summary>
 /// <param name="time">Inherited code: Requires comment 1.</param>
 /// <param name="days">Inherited code: Requires comment 2.</param>
 /// <returns>Inherited code: Requires comment 3.</returns>
 public static DateTime? AddDays(DateTime time, int days)
 {
     System.Globalization.Calendar cal = new CultureInfo("en-US").Calendar;
     try
     {
         return cal.AddDays(time, days);
     }
     catch (ArgumentException)
     {
         return null;
     }
 }