private void CleanupParticle(XmlSchemaParticle particle) {
if (particle is XmlSchemaElement) {
CleanupElement((XmlSchemaElement)particle);
}
else if (particle is XmlSchemaGroupBase) {
foreach(XmlSchemaParticle p in ((XmlSchemaGroupBase)particle).Items) {
CleanupParticle(p);
}
}
}