Create the color map SLD format from a list of values.
        :rtype: str

def getColorMapAsDiscreetSLD(self, uniqueValues, nodata=-9999):
        """
        Create the color map SLD format from a list of values.
        :rtype: str
        """
        colorMap = ET.Element('ColorMap', type='values')
        # Add a line for the no-data values (nv)
        ET.SubElement(colorMap, 'ColorMapEntry', color='#000000', quantity=str(nodata), label='NoData', opacity='0.0')

        for value in uniqueValues:
            red, green, blue = self.getColorForValue(value)
            hexRGB = '#%02X%02X%02X' % (red,
                                        green,
                                        blue)

            ET.SubElement(colorMap, 'ColorMapEntry', color=hexRGB, quantity=str(value), label=str(value), opacity=str(self.alpha))

        return ET.tostring(colorMap)