How to extend sap.ui.core.Item control

Hi there,

I have a requirement where i should show checkboxes beside the individual items in a listbox. I want to extend the sap.ui.core.Item to have a check box. When i was trying that i couldn't find a renderer file.

Can you let me know how to find the renderer file for this control(sap.ui.core.Item)

OR

Let me know if there is a chance to have a checkbox beside every item in the list.

Thanks,

Pradeep