<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def createPlotDataItem(self):
 """ Creates a PyQtGraph PlotDataItem from the config values """

        antialias = self.antiAliasCti.configValue

        color = self.penColor
        if self.lineCti.configValue:
            pen = QtGui.QPen()
            pen.setCosmetic(True)
            pen.setColor(color)
            pen.setWidthF(self.lineWidthCti.configValue)
            pen.setStyle(self.lineStyleCti.configValue)
            shadowCti = self.lineCti.findByNodePath('shadow')
            shadowPen = shadowCti.createPen(altStyle=pen.style(), altWidth=2.0 * pen.widthF())
        else:
            pen = None
            shadowPen = None

        drawSymbols = self.symbolCti.configValue
        symbolShape = self.symbolShapeCti.configValue if drawSymbols else None
        symbolSize  = self.symbolSizeCti.configValue if drawSymbols else 0.0
        symbolPen = None # otherwise the symbols will also have dotted/solid line.
        symbolBrush = QtGui.QBrush(color) if drawSymbols else None

        plotDataItem = pg.PlotDataItem(antialias=antialias, pen=pen, shadowPen=shadowPen,
                                       symbol=symbolShape, symbolSize=symbolSize,
                                       symbolPen=symbolPen, symbolBrush=symbolBrush)
        return plotDataItem