private String resolveMethodName(long methodId, byte methodType) {
        MethodRef method = jfr.methods.get(methodId);
        if (method == null) {
            return "unknown";
        }

        ClassRef cls = jfr.classes.get(method.cls);
        byte[] className = jfr.symbols.get(cls.name);
        byte[] methodName = jfr.symbols.get(method.name);

        if (className == null || className.length == 0 || isNativeFrame(methodType)) {
            return new String(methodName, StandardCharsets.UTF_8);
        } else {
            String classStr = toJavaClassName(className, 0);
            if (methodName == null || methodName.length == 0) {
                return classStr;
            }
            String methodStr = new String(methodName, StandardCharsets.UTF_8);
            return classStr + '.' + methodStr;
        }
    }
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