public void addMXBean(String key, MXBean mxBean) {
		cachedMxBeans.put(key, mxBean);
	}
Add the monitor MXBean into the storage, with the domain name as the key.
@param key is the domain name of JMX
@param mxBean is the monitor MXBean
ngrinder-core/src/main/java/org/ngrinder/monitor/agent/MXBeanStorage.java