@Override
    public Iterable<DefaultLogicalVertex> getVertices() {
        return verticesSorted;
    }
@Test
    public void testGetVertices() {
        // vertices from getVertices() should be topologically sorted
        final Iterable<JobVertex> jobVertices =
                jobGraph.getVerticesSortedTopologicallyFromSources();
        final Iterable<DefaultLogicalVertex> logicalVertices = logicalTopology.getVertices();

        assertEquals(Iterables.size(jobVertices), Iterables.size(logicalVertices));

        final Iterator<JobVertex> jobVertexIterator = jobVertices.iterator();
        final Iterator<DefaultLogicalVertex> logicalVertexIterator = logicalVertices.iterator();
        while (jobVertexIterator.hasNext()) {
            assertVertexAndConnectedResultsEquals(
                    jobVertexIterator.next(), logicalVertexIterator.next());
        }
    }