public static <V, E extends GEdge<V>> List<V> getVerticesInPreOrder(GDirectedGraph<V, E> g,
			GraphNavigator<V, E> navigator) {
		List<V> preOrder = DepthFirstSorter.preOrder(g, navigator);
		return preOrder;
	}
Returns the vertices of the graph in pre-order.   Pre-order is the order the vertices
are encountered when performing a depth-first traversal.

@param g the graph
@param navigator the knower of the direction the graph should be traversed
@return the vertices
Ghidra/Framework/Graph/src/main/java/ghidra/graph/GraphAlgorithms.java