+ return Object.values(previous);
+}
+
+function addEdge(e: Edge) {
+ current[`${e[0]}|${e[1]}`] = e;
+}
+
+function previousEdge(): string {
+ return stack[stack.length - 1];
+}
+
+function formatLine(line: Line<any>): string {
+ const description = line.description ? ` (${line.description})` : '';
+ if (line.form === undefined)
+ return `${line.constructor.name}${description}`;
+ return `${line.form.name}-${line.id}${description}`;