### Question:
JenaConnection implements RDFConnection { @Override public boolean exists(ID subject, UID predicate, NODE object, UID context, boolean includeInferred) { return graph.contains(convert(context), convert(subject), convert(predicate), convert(object)); } JenaConnection(DatasetGraph graph, Dataset dataset, JenaDialect dialect); @Override RDFBeanTransaction beginTransaction(boolean readOnly, int txTimeout, int isolationLevel); @Override void clear(); @Override void close(); @Override BID createBNode(); @SuppressWarnings("unchecked") @Override Q createUpdate(UpdateLanguage<D, Q> updateLanguage, D definition); @SuppressWarnings("unchecked") @Override Q createQuery(QueryLanguage<D, Q> queryLanguage, D definition); @Override boolean exists(ID subject, UID predicate, NODE object, UID context, boolean includeInferred); @Override CloseableIterator<STMT> findStatements(ID subject, UID predicate, NODE object, UID context, boolean includeInferred); @Override long getNextLocalId(); @Override void remove(ID subject, UID predicate, NODE object, UID context); @Override void update(Collection<STMT> removedStatements, Collection<STMT> addedStatements); @Override QueryOptions getQueryOptions(); @Override InferenceOptions getInferenceOptions();  }### Answer:
@Test public void Exists() { UID context = new UID(TEST.NS); assertFalse(connection.exists(null, null, null, context, false)); connection.update(null, Collections.singleton(new STMT(new BID(), RDF.type, RDFS.Class, context))); assertTrue(connection.exists(null, null, null, context, false)); }