jodd-json/src/main/java/jodd/json/TypeJsonSerializerMap.java
protected TypeJsonSerializer lookupSerializer(final Class type) {
		TypeJsonSerializer tjs = map.get(type);

		if (tjs == null) {
			if (defaultSerializerMap != null) {
				tjs = defaultSerializerMap.map.get(type);
			}
		}

		return tjs;
	}
protected TypeJsonSerializer lookupSerializer(final Class type) {
		TypeJsonSerializer tjs = map.get(type);

		if (tjs == null) {
			if (defaultSerializerMap != null) {
				tjs = defaultSerializerMap.map.get(type);
			}
		}

		return tjs;
	}
Get type serializer from map. First the current map is used.
If element is missing, default map will be used, if exist.