### Question:
HMapIDW extends HMapID implements Writable { @Override public int size() { if (!isDecoded()) { return keys.length; } return super.size(); } HMapIDW(); void readFields(DataInput in); void decode(); boolean isDecoded(); void write(DataOutput out); byte[] serialize(); static HMapIDW create(DataInput in); static HMapIDW create(byte[] bytes); static void setLazyDecodeFlag(boolean b); static boolean getLazyDecodeFlag(); int[] getKeys(); double[] getValues(); void plus(HMapIDW m); @Override int size();  }### Answer:
@Test public void testBasic() throws IOException { HMapIDW m = new HMapIDW(); m.put(2, 5.0); m.put(1, 22.0); double value; assertEquals(m.size(), 2); value = m.get(2); assertTrue(value == 5.0); value = m.remove(2); assertEquals(m.size(), 1); value = m.get(1); assertTrue(value == 22.0); }