### Question:
DataTypeStore { public void index(final String uuid, final DataType dataType) { dataTypes.put(uuid, dataType); }  DataType get(final String uuid); void index(final String uuid,
                      final DataType dataType); void clear(); int size(); List<DataType> getTopLevelDataTypes(); List<DataType> all(); void unIndex(final String uuid);  }### Answer:
@Test public void testIndex() { assertEquals(1, store.size()); final DataType secondDataType = mock(DataType.class); final String secondUUID = "789"; store.index(secondUUID, secondDataType); assertEquals(2, store.size()); assertEquals(dataType, store.get(uuid)); assertEquals(secondDataType, store.get(secondUUID)); }