@Override
    public Proto load(String path, Proto importer) throws Exception
    {
        switch (protoSearchStrategy)
        {
            case ALL:
                return searchFromAll(path, importer);

            case PROTO_PATH_ONLY:
                return searchFromProtoPathOnly(path, importer);

            case PROTO_PATH_AND_CLASSPATH:
                return searchFromProtoPathAndClasspath(path, importer);

            default:
                return searchFromAll(path, importer);
        }
    }
Standard JVM property.
See https://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html
protostuff-parser/src/main/java/io/protostuff/parser/DefaultProtoLoader.java