archaius-core/src/main/java/com/netflix/config/jmx/BaseConfigMBean.java
@Override
	public void updateProperty(String key, String value) {
	    if (config instanceof ConcurrentCompositeConfiguration) {
	        ((ConcurrentCompositeConfiguration) config).setOverrideProperty(key, value);
	    } else {
		    config.setProperty(key, value);
	    }
	}
@Override
	public void updateProperty(String key, String value) {
	    if (config instanceof ConcurrentCompositeConfiguration) {
	        ((ConcurrentCompositeConfiguration) config).setOverrideProperty(key, value);
	    } else {
		    config.setProperty(key, value);
	    }
	}
Calls <code>config.setProperty()</code>. If the underlying configuration
is {@link ConcurrentCompositeConfiguration}, it calls {@link ConcurrentCompositeConfiguration#setOverrideProperty(String, Object)}
instead.