code: def _drawBackground(self, scene, painter, rect):
          
          rect = scene.sceneRect()
          if scene == self.uiChartVIEW.scene():
              self.renderer().drawGrid(painter,
                                       rect,
                                       self.showGrid(),
                                       self.showColumns(),
                                       self.showRows())
          elif scene == self.uiXAxisVIEW.scene():
              self.renderer().drawAxis(painter, rect, self.horizontalAxis())
          elif scene == self.uiYAxisVIEW.scene():
              self.renderer().drawAxis(painter, rect, self.verticalAxis())
docs: Draws the backgroud for a particular scene within the charts.
          
          :param      scene   | <XChartScene>
                      painter | <QPainter>
                      rect    | <QRectF>