@Test
 public void setMultipleParameters() {
   request.setParameter("key1", "value1");
   request.setParameter("key2", "value2");
   Map<String, Object> params = new HashMap<String, Object>(2);
   params.put("key1", "newValue1");
   params.put("key3", new String[] {"value3A", "value3B"});
   request.setParameters(params);
   String[] values1 = request.getParameterValues("key1");
   assertEquals(1, values1.length);
   assertEquals("newValue1", request.getParameter("key1"));
   assertEquals("value2", request.getParameter("key2"));
   String[] values3 = request.getParameterValues("key3");
   assertEquals(2, values3.length);
   assertEquals("value3A", values3[0]);
   assertEquals("value3B", values3[1]);
 }
 @Test
 public void nullParameterName() {
   assertNull(request.getParameter(null));
   assertNull(request.getParameterValues(null));
 }