### Question:
DataTypeStore { public DataType get(final String uuid) { return dataTypes.get(uuid); }  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 testGetWhenItReturnsNull() { assertNull(store.get("456")); }
@Test public void testGetWhenItDoesNotReturnNull() { assertNotNull(store.get(uuid)); assertEquals(dataType, store.get(uuid)); }