assertEquals("Unexpected stored properties: " + info, F.asMap(key1, "1", key2, "2"), info.properties());
info = mgr.updateProperties(ROOT_ID, fileId, fileName, F.<String, String>asMap(key1, null));
assertEquals("Unexpected stored properties: " + info, F.asMap(key2, "2"), info.properties());
info = mgr.updateProperties(ROOT_ID, fileId, fileName, F.<String, String>asMap(key2, null));
assertNull("Expects empty properties are not stored: " + info, getFieldValue(info, "props"));
assertEquals("Expects empty properties are not stored: " + info, Collections.emptyMap(), info.properties());