@Test
@SuppressWarnings("unchecked")
public void testSortedMapWritable() {

  Text[] keys = {
      new Text("key1"),
      new Text("key2"),
      new Text("key3"),
  };
  
  BytesWritable[] values = {
      new BytesWritable("value1".getBytes()),
      new BytesWritable("value2".getBytes()),
      new BytesWritable("value3".getBytes())
  };
  SortedMapWritable inMap = new SortedMapWritable();
  for (int i = 0; i < keys.length; i++) {
    inMap.put(keys[i], values[i]);
  }
  
  assertEquals(0, inMap.firstKey().compareTo(keys[0]));
  assertEquals(0, inMap.lastKey().compareTo(keys[2]));
  SortedMapWritable outMap = new SortedMapWritable(inMap);
  assertEquals(inMap.size(), outMap.size());
  
  for (Map.Entry<WritableComparable, Writable> e: inMap.entrySet()) {
    assertTrue(outMap.containsKey(e.getKey()));
    assertEquals(0, ((WritableComparable) outMap.get(e.getKey())).compareTo(
        e.getValue()));
  }
  
  // Now for something a little harder...
  
  Text[] maps = {
      new Text("map1"),
      new Text("map2")
  };
  
  SortedMapWritable mapOfMaps = new SortedMapWritable();
  mapOfMaps.put(maps[0], inMap);
  mapOfMaps.put(maps[1], outMap);
  
  SortedMapWritable copyOfMapOfMaps = new SortedMapWritable(mapOfMaps);
  for (int i = 0; i < maps.length; i++) {
    assertTrue(copyOfMapOfMaps.containsKey(maps[i]));
    SortedMapWritable a = (SortedMapWritable) mapOfMaps.get(maps[i]);
    SortedMapWritable b = (SortedMapWritable) copyOfMapOfMaps.get(maps[i]);
    assertEquals(a.size(), b.size());
    for (Writable key: a.keySet()) {
      assertTrue(b.containsKey(key));
      
      // This will work because we know what we put into each set
      
      WritableComparable aValue = (WritableComparable) a.get(key);
      WritableComparable bValue = (WritableComparable) b.get(key);
      assertEquals(0, aValue.compareTo(bValue));
    }
  }
}