### Question:
MetadataFileCache extends AbstractFileCache<String> implements IMetadataCache { @Override public synchronized Metadata getMetadata(IWiki wiki) throws CacheException { final String key = wiki.getApiUrl(); if (this.containsKey(key)) { Object metadataObject = null; try { metadataObject = SerializationUtils.deserialize(this.get(key)); if (metadataObject == null) { return null; } else if (metadataObject instanceof Metadata) { return (Metadata) metadataObject; } else { this.remove(key); String message = Messages.getString("MetadataFileCache.Error.Deserialize"); LOGGER.error(message); throw new CacheException(message); } } catch (SerializationException e) { this.remove(key); String message = Messages.getString("MetadataFileCache.Error.Deserialize"); LOGGER.warn(message, e); throw new CacheException(message, e); } } else { return null; } } MetadataFileCache(final File cacheDirectory, final int maxAgeInSeconds); @Override synchronized Metadata getMetadata(IWiki wiki); @Override synchronized void put(IWiki wiki, Metadata metadata);  }### Answer:
@Test public void testGetMetadataNull() throws CacheException { TestWiki wiki = new TestWiki(); assertNull(underTest.getMetadata(wiki)); }