ExceptionUtils { public static String buildExceptionMessage( final String message, final Throwable cause) { if (null == cause) { return message; } final StringBuilder sb = new StringBuilder(); if (null != message) { sb.append(message).append("; "); } sb.append("nested exception is ").append(cause); return sb.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 testBuildExceptionMessage() { assertNull(ExceptionUtils.buildExceptionMessage(null, null)); for (int i = 0; i < 100; ++i) { assertNotNull(ExceptionUtils.buildExceptionMessage(randomUUID().toString(), new Throwable())); } }