### Question:
MetadataKey { static MDSKey createValueRowKey(MetadataEntity metadataEntity, @Nullable String key) { MDSKey.Builder builder = getMDSKeyPrefix(metadataEntity, VALUE_ROW_PREFIX); if (key != null) { builder.add(key); } return builder.build(); } private  MetadataKey();   }### Answer:
@Test public void testGetMDSValueKey() { MDSKey mdsValueKey = MetadataKey.createValueRowKey(new ApplicationId("ns1", "app1").toMetadataEntity(), "key1"); MDSKey.Splitter split = mdsValueKey.split(); split.skipBytes(); Assert.assertEquals(MetadataEntity.APPLICATION, split.getString()); Assert.assertEquals(MetadataEntity.NAMESPACE, split.getString()); Assert.assertEquals("ns1", split.getString()); Assert.assertEquals(MetadataEntity.APPLICATION, split.getString()); Assert.assertEquals("app1", split.getString()); Assert.assertEquals("key1", split.getString()); Assert.assertFalse(split.hasRemaining()); }