boolean writeNullStringAsEmpty = false;
boolean writeNullBooleanAsFalse = false;
boolean writeNullListAsEmpty = false;
JSONField annotation = fieldInfo.getAnnotation(JSONField.class);
if (annotation != null) {
for (SerializerFeature feature : annotation.serialzeFeatures()) {
if (feature == SerializerFeature.WriteMapNullValue) {
writeNull = true;
} else if (feature == SerializerFeature.WriteNullNumberAsZero) {
writeNullNumberAsZero = true;
} else if (feature == SerializerFeature.WriteNullStringAsEmpty) {