* @see com.dooapp.gaedo.blueprints.queries.executable.AbstractGraphExecutableQuery#getVerticesToExamine()
*/
@Override
public GraphExecutionPlan getExecutionPlan() {
Iterable<Vertex> verticesToExamine = getVerticesToExamine();
VertexTest toUse = test;
if(verticesToExamine==null) {
// First step is to get all possible query root vertices
SortedMap<VertexSet, VertexTest> possibleRoots = getPossibleRootsOf(test);
// extract the set from the map. Too bad it can't be provided directly by Java
SortedSet<VertexSet> rootsSet = new TreeSet<VertexSet>(possibleRoots.comparator());