### Question:
JavaScriptEngineService implements ScriptEngineService { @Override public List<? extends Instrumenter> createInstrumenters() throws EngineException { if (m_dcrContext != null) { return asList(new JavaDCRInstrumenter(m_dcrContext)); } return emptyList(); } JavaScriptEngineService(DCRContext dcrContext);  JavaScriptEngineService(); @Override List<? extends Instrumenter> createInstrumenters(); @Override ScriptEngine createScriptEngine(ScriptLocation script);  }### Answer:
@Test public void testCreateInstrumenter() throws Exception { final DCRContext context = DCRContextImplementation.create(null); final List<? extends Instrumenter> instrumenters = new JavaScriptEngineService(context).createInstrumenters(); assertEquals(1, instrumenters.size()); assertEquals("byte code transforming instrumenter for Java", instrumenters.get(0).getDescription()); }
@Test public void testCreateInstrumenterWithNoInstrumentation() throws Exception { final List<? extends Instrumenter> instrumenters = new JavaScriptEngineService().createInstrumenters(); assertEquals(0, instrumenters.size()); }