@Test(timeout = 1000)
public void testPutAll() {

  SortedMapWritable map1 = new SortedMapWritable();
  SortedMapWritable map2 = new SortedMapWritable();
  map1.put(new Text("key"), new Text("value"));
  map2.putAll(map1);
  assertEquals("map1 entries don't match map2 entries", map1, map2);
  assertTrue(
      "map2 doesn't have class information from map1",
      map2.classToIdMap.containsKey(Text.class)
          && map2.idToClassMap.containsValue(Text.class));
}