BatchMutation { public boolean isEmpty() { return mutationMap.isEmpty() ; } BatchMutation(Serializer<K> serializer, BatchSizeHint sizeHint);  BatchMutation(Serializer<K> serializer); private  BatchMutation(Serializer<K> serializer, Map<ByteBuffer,Map<String,List<Mutation>>> mutationMap, BatchSizeHint sizeHint); BatchMutation<K> addInsertion(K key, List<String> columnFamilies,
      Column column); BatchMutation<K> addSuperInsertion(K key, List<String> columnFamilies,
      SuperColumn superColumn); BatchMutation<K> addCounterInsertion(K key, List<String> columnFamilies, CounterColumn counterColumn); BatchMutation<K> addSuperCounterInsertion(K key, List<String> columnFamilies, 
      CounterSuperColumn counterSuperColumn); BatchMutation<K> addDeletion(K key, List<String> columnFamilies, Deletion deletion); Map<ByteBuffer,Map<String,List<Mutation>>> getMutationMap(); BatchMutation<K> makeCopy(); boolean isEmpty(); int getSize();  }
@Test public void testIsEmpty() { assertTrue(batchMutate.isEmpty()); Column c1 = new Column(StringSerializer.get().toByteBuffer("c_name")); c1.setValue(StringSerializer.get().toByteBuffer("c_val")); c1.setTimestamp(System.currentTimeMillis()); batchMutate.addInsertion("key1", columnFamilies, c1); assertFalse(batchMutate.isEmpty()); CounterColumn cc1 = new CounterColumn(StringSerializer.get().toByteBuffer("c_name"), 13); batchMutate.addCounterInsertion("key1", columnFamilies, cc1); assertFalse(batchMutate.isEmpty()); }