//try here to get the resource set to our existing proxy!
ResourceSet resourceSet = DataItemHelper.getInstance().getProxyForDataItem(myComponent).getResourceSet();
		
TransactionalEditingDomain editingDomain = TransactionUtil.getEditingDomain(resourceSet);
if (editingDomain == null) {
  // Not yet existing, create one
  LoggerPlugin.getDefault().debug("Editing Domain is created");
  editingDomain = TransactionalEditingDomain.Factory.INSTANCE.createEditingDomain(resourceSet);
}