Method sort

corpus/java/training/antlr4-tool/org/antlr/v4/misc/Graph.java:90–105

DFS-based topological sort. A valid sort is the reverse of the post-order DFA traversal. Amazingly simple but true. For sorting, I'm not following convention here since ANTLR needs the opposite. Here's what I assume for sorting: If there exists an edge u -> v then u depends on v and v

()

	 *  I want.
	 */
	public List<T> sort() {
		Set<Node<T>> visited = new OrderedHashSet<Node<T>>();
		ArrayList<T> sorted = new ArrayList<T>();
		while ( visited.size() < nodes.size() ) {
			// pick any unvisited node, n
			Node<T> n = null;
			for (Node<T> tNode : nodes.values()) {
				n = tNode;
				if ( !visited.contains(n) ) break;
			}
			if (n!=null) { // if at least one unvisited
				DFS(n, visited, sorted);
			}
		}
		return sorted;
	}

	public void DFS(Node<T> n, Set<Node<T>> visited, ArrayList<T> sorted) {
		if ( visited.contains(n) ) return;