public static Layer CreateNew(string label,SvgDocument doc)
{
Layer layer =doc.CreateElement(doc.Prefix, "layer", doc.NamespaceURI) as Layer;
doc.AcceptChanges =true;
layer =doc.AddDefsElement(layer) as Layer;
doc.AcceptChanges =false;
layer.Label = label;
doc.Layers.Add(layer);
return layer;
}