public static StringBuilder appendWithBlankCheck(String str, String defaultValue, StringBuilder appender) {
        if (isNotBlank(str)) {
            appender.append(str);
        } else {
            appender.append(defaultValue);
        }
        return appender;
    }
@Test
    public void testAppendWithBlankCheck() {
        Assert.assertEquals("bar", EagleEyeCoreUtils.appendWithBlankCheck(
                null, "bar", new StringBuilder()).toString());
        Assert.assertEquals("foo", EagleEyeCoreUtils.appendWithBlankCheck(
                "foo", "bar", new StringBuilder()).toString());
    }