@Override
        public byte[] doInTransform(Instrumentor instrumentor, ClassLoader classLoader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws InstrumentException {
            InstrumentClass target = instrumentor.getInstrumentClass(classLoader, className, classfileBuffer);
            InstrumentMethod constructor = target.getConstructor("java.lang.String");
            if (constructor == null) {
                return null;
            }
            target.addField(HystrixKeyNameAccessor.class);
            constructor.addInterceptor(HystrixKeyConstructInterceptor.class);
            return target.toBytecode();
        }
Any Pinpoint profiler plugin must implement ProfilerPlugin interface.
ProfilerPlugin declares only one method {@link #setup(ProfilerPluginSetupContext)}.
You should implement the method to do whatever you need to setup your plugin with the passed ProfilerPluginSetupContext object.

@author Jiaqi Feng
@author HyunGil Jeong
agent-module/plugins/hystrix/src/main/java/com/navercorp/pinpoint/plugin/hystrix/HystrixPlugin.java