ExceptionUtils { public static String getStackTraceOf( final Throwable e) { if (null == e) { return null; } final StringWriter writer = new StringWriter(); final PrintWriter w = new PrintWriter(writer); e.printStackTrace(w); return writer.toString(); }  static String buildExceptionMessage(
      final String message,
      final Throwable cause); static String trace(); static String trace(
      final StackTraceElement[] elements); static String trace(
      final StackTraceElement[] elements,
      final int start,
      final int end); static String getStackTraceOf(
      final Throwable e); static StackTraceElement[] concat(final StackTraceElement[] left,
      final StackTraceElement[] right);  }
@Test public void testGetStackTraceOf() { final Throwable e = new Throwable(); assertNull(ExceptionUtils.getStackTraceOf(null)); assertNotNull(ExceptionUtils.getStackTraceOf(e)); }