/// <summary>
 /// Initializes a new instance of the ColumnEventArgs class with
 /// the specified Column source, column index and event type
 /// </summary>
 /// <param name="source">The Column that Raised the event</param>
 /// <param name="index">The index of the Column</param>
 /// <param name="eventType">The type of event</param>
 /// <param name="oldValue">The old value of the changed property</param>
 public I3ColumnEventArgs(I3Column source, int index, I3ColumnEventType eventType, object oldValue) : base()
 {
     this.source    = source;
     this.index     = index;
     this.eventType = eventType;
     this.oldValue  = oldValue;
 }
 /// <summary>
 /// Initializes a new instance of the ColumnEventArgs class with
 /// the specified Column source, column index and event type
 /// </summary>
 /// <param name="source">The Column that Raised the event</param>
 /// <param name="eventType">The type of event</param>
 /// <param name="oldValue">The old value of the changed property</param>
 public I3ColumnEventArgs(I3Column source, I3ColumnEventType eventType, object oldValue) : this(source, -1, eventType, oldValue)
 {
 }