### Question:
IRODSFileSystemSingletonWrapper implements Serializable { public static synchronized IRODSFileSystem instance() { if (irodsFileSystem == null) { try { irodsFileSystem = IRODSFileSystem.instance(); } catch (JargonException e) { throw new JargonRuntimeException("unable to create instance"); } } return irodsFileSystem; } protected  IRODSFileSystemSingletonWrapper(); static synchronized IRODSFileSystem instance();  }### Answer:
@Test public void testInstance() throws JargonException { IRODSFileSystem irodsFileSystem = IRODSFileSystemSingletonWrapper.instance(); Assert.assertNotNull(irodsFileSystem); }