protected boolean isNativeFrame(byte methodType) {
        // In JDK Flight Recorder, TYPE_NATIVE denotes Java native methods,
        // while in async-profiler, TYPE_NATIVE is for C methods
        return methodType == TYPE_NATIVE && jfr.getEnumValue("jdk.types.FrameType", TYPE_KERNEL) != null ||
                methodType == TYPE_CPP ||
                methodType == TYPE_KERNEL;
    }
JFRConverter is copied from one.jfr.JfrConverter. Because need to
add collectMultiEvents and getEventAggregator methods, to parse 
and process multiple events at one time.
oap-server/server-library/library-async-profiler-jfr-parser/src/main/java/one/jfr/JFRConverter.java