### Question:
DailyLogListener extends RotateLogListener { protected OutputStream getCompressedOutputStream(File f) throws IOException{ OutputStream os = new BufferedOutputStream(new FileOutputStream(f)); if (getCompressionFormat() == ZIP) { ZipOutputStream ret = new ZipOutputStream(os); ret.putNextEntry(new ZipEntry(logName)); return ret; } else { return new GZIPOutputStream(os); } } DailyLogListener(); void setConfiguration(Configuration cfg); void deleteOldLogs(); String getSuffix(); void setSuffix(String suffix); String getPrefix(); void setPrefix(String prefix); int getRotateCount(); void setRotateCount(int rotateCount); DateFormat getDateFmt(); void setDateFmt(DateFormat dateFmt); String getLastDate(); void setLastDate(String lastDate); String getCompressedSuffix(); void setCompressedSuffix(String compressedSuffix); long getMaxAge(); void setMaxAge(long maxAge); String getDeleteRegex(); void setDeleteRegex(String deleteRegex); int getCompressionFormat(); void setCompressionFormat(int compressionFormat); int getCompressionBufferSize(); void setCompressionBufferSize(int compressionBufferSize);  }### Answer:
@Test public void testGetCompressedOutputStreamThrowsNullPointerException() throws Throwable { DailyLogListener dailyLogListener = new DailyLogListener(); try { dailyLogListener.getCompressedOutputStream(null); fail("Expected NullPointerException to be thrown"); } catch (NullPointerException ex) { } }