private static void assertCommonB(final Traversal<Vertex, Edge> traversal) {
        assertTrue(traversal.hasNext());
        assertTrue(traversal.hasNext());
        final Edge edge = traversal.next();
        assertEquals("knows", edge.label());
        assertEquals(1.0d, edge.<Double>value("weight"), 0.00001d);
        assertFalse(traversal.hasNext());
        assertFalse(traversal.hasNext());
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
@author Daniel Kuppitz (http://gremlin.guru)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/SelectTest.java