getRootNodes method
Implementation
List<Node> getRootNodes(Graph graph) {
final predecessors = <Node, bool>{};
graph.edges.forEach((element) {
predecessors[element.destination] = true;
});
var roots = graph.nodes.where((node) => predecessors[node] == null);
roots.forEach((node) {
nodeData[node]?.layer = layers.length;
});
return roots.toList();
}