It should be available from richfaces-core-api. Please add more info about your deployment.
P.S. it not depends on it but will be good idea to switch to 4.1 M1 - there are four new components and set of fixes/enhancements.
Thank you Ilya,
You are right.
I'll take a look at 4.1 M1 release.
Thnx Ilya, it worked !!