protected Vertex getUnvisitedChildVertex(Vertex vertex, Vertex parent) {
Iterator vertices = vertex.getNeighborIterator();
while (vertices.hasNext()) {
Vertex child = (Vertex) vertices.next();
if (!child.isVisited()) {
return child;
} else {
if (!child.equals(parent)) {
hasCycle = true;
}
}
}
return null;
}
