final List<MutableNode> rootNodes = new ArrayList<>(); for (TableRef tableRef : TopologicalOrderIterator.of(g)) { final List<StepRef> edges = g.getInwardEdges(tableRef); final MutableNode node; switch (edges.size()) {
final List<MutableNode> rootNodes = new ArrayList<>(); for (TableRef tableRef : TopologicalOrderIterator.of(g)) { final List<StepRef> edges = g.getInwardEdges(tableRef); final MutableNode node; switch (edges.size()) {