@Override
        public Traversal<Vertex, Map<String, Long>> get_g_V_groupXaX_byXname_substring_1X_byXconstantX1XX_capXaX() {
            return g.V().<String, Long>group("a").<Vertex>by(v -> v.<String>value("name").substring(0, 1)).by(constant(1l)).cap("a");
        }
Tests that cover lambda steps that are used in embedded cases.
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/LambdaStepTest.java