How to use multi select or checkboxlist in Struts 2

Hi, I'm having a problem using a checkboxlist to update a list in my model and can't find any example of using checkboxlist on the web. Displaying the checkboxes works fine, but not saving their values to the model. And I'm not exactly clear on how the checkboxlist does the conversion

Multiselect tags

Are there any examples of how to write Actions for the multiselect tags such as documentation only explains how to use the tags themselves, but not what the action or model should look like and whether any conversion is required between the two. I have already trawled through nabble to fi