the prefuse visualization toolkit

Hi Prefusians,

I have just read what some people wrote about creating a group but i still have some problem to add some elements to this Group, particulary how to manipulate Tuple in vis.getFocusGroup("groupName")add(tuple). what i want to do is the following: i have a Set of value the form < john,peter,romeo,.....> i want to put all the elements of this set in groupName and then color them since their all nodes in my Graphview,Some examples are wellcoming.

Thanks in advance for your Reply, Christ.