human
Solve the following python programming problem given the following code:
def _mouse_modes(self) : 
    axes = self.client.axes 
    def apply_mode(mode) : 
        self.client.apply_roi (mode.roi ()) 
def on_move(mode) : 
        if mode._drag : 
            self.client.apply_roi (mode.roi ()) 
return [PickMode (axes, move_callback = on_move, roi_callback = self)] 

    
    

    Fix the buggy line: return [PickMode (axes, move_callback = on_move, roi_callback = self)]
assistant
#Here is Python code to fix the buggy line: return [PickMode (axes, move_callback = on_move, roi_callback = self)]
.

return [PickMode (axes, move_callback = on_move, roi_callback = def apply_mode()]