### Question:
FunctionRegistryHolder { public List<String> getAllJarNames() { try (AutoCloseableLock lock = readLock.open()) { return Lists.newArrayList(jars.keySet()); } } FunctionRegistryHolder(); long getVersion(); void addJars(Map<String, List<FunctionHolder>> newJars, long version); void removeJar(String jarName); List<String> getAllJarNames(); List<String> getFunctionNamesByJar(String jarName); ListMultimap<String, DrillFuncHolder> getAllFunctionsWithHolders(AtomicLong version); ListMultimap<String, DrillFuncHolder> getAllFunctionsWithHolders(); ListMultimap<String, String> getAllFunctionsWithSignatures(); List<DrillFuncHolder> getHoldersByFunctionName(String functionName, AtomicLong version); List<DrillFuncHolder> getHoldersByFunctionName(String functionName); boolean containsJar(String jarName); int functionsSize(); String getJarNameByFunctionSignature(String functionName, String functionSignature);  }### Answer:
@Test public void testGetAllJarNames() { ArrayList<String> expectedResult = Lists.newArrayList(newJars.keySet()); compareTwoLists(expectedResult, registryHolder.getAllJarNames()); }