How can access the uibutton ,when apply the UIPanGestureRecognizer to the same button

Question

I am new in ios development.Now, i am developing a small application with GestureRecognizer. In my application has some uibuttons and this buttons respond to UIPanGestureRecognizer. Now i want to identify which button is dragging,when applying the UIPanGestureRecognizer.

if anybody know .please clear my question.