/// <summary>
/// Returns a snapshot image of this group
/// </summary>
/// <param name="imgWidth">Width in pixels of the returned image (height is determined by the number of layers in the group)</param>
/// <returns>Bitmap of the group and sublayers (expanded)</returns>
public System.Drawing.Bitmap Snapshot(int imgWidth)
{
Bitmap bmp = null; // = new Bitmap(imgWidth,imgHeight);
Rectangle rect;
System.Drawing.Graphics g;
bmp = new Bitmap(imgWidth, this.ExpandedHeight);
g = Graphics.FromImage(bmp);
g.Clear(System.Drawing.Color.White);
rect = new Rectangle(0, 0, imgWidth, this.ExpandedHeight);
m_Legend.DrawGroup(g, this, rect, true);
return(bmp);
}