@Test
    public void shouldRename() {
        final Parameters parameters = new Parameters();
        parameters.set(null, "a", "axe", "b", "bat", "c", "cat");

        parameters.rename("a", "z");

        final Map<Object,List<Object>> before = parameters.getRaw();
        assertEquals(3, before.size());
        assertEquals("axe", before.get("z").get(0));
        assertEquals("bat", before.get("b").get(0));
        assertEquals("cat", before.get("c").get(0));
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/ParametersTest.java