### Question:
DailyLogListener extends RotateLogListener { protected void closeCompressedOutputStream(OutputStream os) throws IOException{ if (os instanceof DeflaterOutputStream) ((DeflaterOutputStream)os).finish(); os.close(); } 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 testCloseCompressedOutputStream() throws Throwable { OutputStream os = new DeflaterOutputStream(new PrintStream(new ByteArrayOutputStream()), new Deflater()); DailyLogListener dailyLogListener = new DailyLogListener(); dailyLogListener.closeCompressedOutputStream(os); assertTrue(true, "Test completed without Exception"); }
@Test public void testCloseCompressedOutputStream1() throws Throwable { DailyLogListener dailyLogListener = new DailyLogListener(); OutputStream os = new DataOutputStream(new ByteArrayOutputStream()); dailyLogListener.closeCompressedOutputStream(os); assertEquals(0, ((DataOutputStream) os).size(), "(DataOutputStream) os.size()"); }
@Test public void testCloseCompressedOutputStreamThrowsNullPointerException() throws Throwable { DailyLogListener dailyLogListener = new DailyLogListener(); try { dailyLogListener.closeCompressedOutputStream(null); fail("Expected NullPointerException to be thrown"); } catch (NullPointerException ex) { if (isJavaVersionAtMost(JAVA_14)) { assertNull(ex.getMessage(), "ex.getMessage()"); } else { assertEquals("Cannot invoke \"java.io.OutputStream.close()\" because \"os\" is null", ex.getMessage(), "ex.getMessage()"); } } }