UIComponent binding in cluster environment

There are two posts mentioned about how UIComponent buiding works in cluster environment:

http://www.ateam-oracle.com/rules-and-best-practices-for-jsf-component-binding-in-adf/
https://adfblog.wordpress.com/2014/08/14/adf-for-high-availability/

in short,

• All Manage Beans must implement Serializable.
• UI component bindings must be declared in a bean with shorter scope (backing bean scope or request scope).
• If it needs to be declared in Manage Bean with PageFlowScope (Not recommended), please ensure you declare the binding as transient.
• ......

And interested in the class below:
org.apache.myfaces.trinidad.util.ComponentReference
https://java.net/jira/browse/ADFEMG-202