protected override void InvokeInternal(CommandProcessorContext cpc)
{
// check to see if this name is unique
string msg = null;
if (!ModelHelper.IsUniqueName(typeof(Diagram), _diagrams, _name, true, out msg))
{
throw new InvalidOperationException(msg);
}
var diagram = new Diagram(_diagrams, null);
diagram.Id.Value = Guid.NewGuid().ToString("N");
diagram.LocalName.Value = _name;
_diagrams.AddDiagram(diagram);
XmlModelHelper.NormalizeAndResolve(diagram);
_created = diagram;
}