Draws the inputed item as a bar graph.
        
        :param      item    | <XChartDatasetItem>
                    painter | <QPainter>
                    option  | <QStyleOptionGraphicsItem>

def drawItem(self, item, painter, option):
        """
        Draws the inputed item as a bar graph.
        
        :param      item    | <XChartDatasetItem>
                    painter | <QPainter>
                    option  | <QStyleOptionGraphicsItem>
        """
        dataset = item.dataset()
        
        painter.save()
        painter.setRenderHint(painter.Antialiasing)
        
        pen = QPen(dataset.color())
        pen.setWidth(3)
        painter.setPen(pen)
        painter.setBrush(Qt.NoBrush)
        painter.drawPath(item.path())
        
        if self.showPoints():
            palette = QApplication.palette()
            pen = QPen(palette.color(palette.Base))
            pen.setWidth(2)
            
            painter.setBrush(dataset.color())
            painter.setPen(pen)
            
            for point in item.buildData('ellipses', []):
                painter.drawEllipse(point,
                                    self.pointRadius(),
                                    self.pointRadius())
        
        painter.restore()