HDFSFileSystem extends AbstractFileSystem implements FileSystem { public HadoopFileSystem getHDFSFileSystem() throws FileSystemException { return hdfs; } HDFSFileSystem( final FileName rootName, final FileSystemOptions fileSystemOptions,
                            HadoopFileSystem hdfs ); HadoopFileSystem getHDFSFileSystem();  }
@Test public void testGetHDFSFileSystem() throws FileSystemException { assertEquals( hadoopFileSystem, hdfsFileSystem.getHDFSFileSystem() ); }