### Question:
BrooklynStorageImpl implements BrooklynStorage { @Override public <K, V> ConcurrentMap<K, V> getMap(final String id) { return datagrid.<K,V>getMap(id); } BrooklynStorageImpl(DataGrid datagrid); @VisibleForTesting DataGrid getDataGrid(); @Override Reference<T> getReference(final String id); @Override Reference<List<T>> getNonConcurrentList(final String id); @Override ConcurrentMap<K, V> getMap(final String id); @Override void remove(String id); @Override void terminate(); boolean isMostlyEmpty(); @Override Map<String, Object> getStorageMetrics(); @Override String toString();  }### Answer:
@Test public void testCreateMapReturnsSameEachTime() throws Exception { storage.getMap("mykey").put("k1", "v1"); assertEqualsCommutative(storage.getMap("mykey"), ImmutableMap.of("k1", "v1")); }