final Node columnNode = resolver.getNode(columnUuid);
UnresolvedReference unresolvedColumn = null;
if (columnNode == null) {
unresolvedColumn = resolver.addUnresolvedReference(columnUuid);
unresolvedColumn.addMixin(JcrId.TRANSFORMED);
} else if (!columnNode.isNodeType(JcrId.TRANSFORMED)) {
columnNode.addMixin(JcrId.TRANSFORMED);
}
// nested children are inputs which are the referenced source columns