### Question:
VirtuosoRepository implements Repository { public VirtuosoRepositoryConnection openConnection() { try { java.sql.Connection connection = ds.getConnection(); return new VirtuosoRepositoryConnection(idSequence, converter, prefetchSize, defGraph, allowedGraphs, connection); } catch (SQLException e) { logger.error("Connection to " + host + " FAILED."); throw new RepositoryException(e); } } VirtuosoRepository(String hostlist, String user, String password);  VirtuosoRepository(String host, int port, String user, String password);  VirtuosoRepository(String hostlist, String user, String password, String defGraph);  VirtuosoRepository(String host, int port, String user, String password, String defGraph); @Override void close(); @Override RT execute(RDFConnectionCallback<RT> operation); @Override void export(Format format, Map<String, String> ns2prefix, UID context, OutputStream out); @Override void export(Format format, UID context, OutputStream out); VirtuosoRepositoryConnection openConnection(); File getDataDir(); int getFetchSize(); void initialize(); @Override void load(Format format, InputStream is, UID context, boolean replace); boolean isInitialized(); void setDataDir(File dataDir); void setFetchSize(int sz); void setSources(RDFSource... sources); void setAllowedGraphs(Collection<UID> allowedGraphs); void setInitialPoolSize(int initialPoolSize); void setMinPoolSize(int minPoolSize); void setMaxPoolSize(int maxPoolSize);  }### Answer:
@Test public void OpenConnection() { RDFConnection connection = repository.openConnection(); try { assertNotNull(connection); } finally { connection.close(); } }