### Question:
SignalManager { public void signalReady(Constraints viewConstraints) { try { rootFileSystem.mkdirs(signalDirectory); } catch (IOException e) { throw new DatasetIOException("Unable to create signal manager directory: " + signalDirectory, e); } String normalizedConstraints = getNormalizedConstraints(viewConstraints); Path signalPath = new Path(signalDirectory, normalizedConstraints); try{ FSDataOutputStream os = rootFileSystem.create(signalPath, true); os.close(); } catch (IOException e) { throw new DatasetIOException("Could not access signal path: " + signalPath, e); } } SignalManager(FileSystem fileSystem, Path signalDirectory); void signalReady(Constraints viewConstraints); long getReadyTimestamp(Constraints viewConstraints); static String getNormalizedConstraints(Constraints constraints);  }### Answer:
@Test public void testSignalDirectoryCreatedOnSignal() throws IOException { SignalManager manager = new SignalManager(fileSystem, testDirectory); Assert.assertFalse("Signal directory shouldn't exist before signals", fileSystem.exists(testDirectory)); Constraints constraints = new Constraints(DatasetTestUtilities.USER_SCHEMA). with("email", "signalCreatesDir@domain.com"); manager.signalReady(constraints); Assert.assertTrue("Signal directory created on signals", fileSystem.exists(testDirectory)); }