<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _create_controls(self, can_kill):
 """ Creates the button controls, and links them to event handlers """

        DEBUG_MSG("_create_controls()", 1, self)
        # Need the following line as Windows toolbars default to 15x16

        self.SetToolBitmapSize(wx.Size(16,16))
        self.AddSimpleTool(_NTB_X_PAN_LEFT, _load_bitmap('stock_left.xpm'),
                           'Left', 'Scroll left')
        self.AddSimpleTool(_NTB_X_PAN_RIGHT, _load_bitmap('stock_right.xpm'),
                           'Right', 'Scroll right')
        self.AddSimpleTool(_NTB_X_ZOOMIN, _load_bitmap('stock_zoom-in.xpm'),
                           'Zoom in', 'Increase X axis magnification')
        self.AddSimpleTool(_NTB_X_ZOOMOUT, _load_bitmap('stock_zoom-out.xpm'),
                           'Zoom out', 'Decrease X axis magnification')
        self.AddSeparator()
        self.AddSimpleTool(_NTB_Y_PAN_UP,_load_bitmap('stock_up.xpm'),
                           'Up', 'Scroll up')
        self.AddSimpleTool(_NTB_Y_PAN_DOWN, _load_bitmap('stock_down.xpm'),
                           'Down', 'Scroll down')
        self.AddSimpleTool(_NTB_Y_ZOOMIN, _load_bitmap('stock_zoom-in.xpm'),
                           'Zoom in', 'Increase Y axis magnification')
        self.AddSimpleTool(_NTB_Y_ZOOMOUT, _load_bitmap('stock_zoom-out.xpm'),
                           'Zoom out', 'Decrease Y axis magnification')
        self.AddSeparator()
        self.AddSimpleTool(_NTB_SAVE, _load_bitmap('stock_save_as.xpm'),
                           'Save', 'Save plot contents as images')
        self.AddSeparator()

        bind(self, wx.EVT_TOOL, self._onLeftScroll, id=_NTB_X_PAN_LEFT)
        bind(self, wx.EVT_TOOL, self._onRightScroll, id=_NTB_X_PAN_RIGHT)
        bind(self, wx.EVT_TOOL, self._onXZoomIn, id=_NTB_X_ZOOMIN)
        bind(self, wx.EVT_TOOL, self._onXZoomOut, id=_NTB_X_ZOOMOUT)
        bind(self, wx.EVT_TOOL, self._onUpScroll, id=_NTB_Y_PAN_UP)
        bind(self, wx.EVT_TOOL, self._onDownScroll, id=_NTB_Y_PAN_DOWN)
        bind(self, wx.EVT_TOOL, self._onYZoomIn, id=_NTB_Y_ZOOMIN)
        bind(self, wx.EVT_TOOL, self._onYZoomOut, id=_NTB_Y_ZOOMOUT)
        bind(self, wx.EVT_TOOL, self._onSave, id=_NTB_SAVE)
        bind(self, wx.EVT_TOOL_ENTER, self._onEnterTool, id=self.GetId())
        if can_kill:
            bind(self, wx.EVT_TOOL, self._onClose, id=_NTB_CLOSE)
        bind(self, wx.EVT_MOUSEWHEEL, self._onMouseWheel)