<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def mmGetPlotUnionSDRActivity(self, title="Union SDR Activity Raster", showReset=False, resetShading=0.25):
 """ Returns plot of the activity of union SDR bits. @param title an optional title for the figure @param showReset if true, the first set of activities after a reset will have a gray background @param resetShading If showReset is true, this float specifies the intensity of the reset background with 0.0 being white and 1.0 being black @return (Plot) plot """

    unionSDRTrace = self.mmGetTraceUnionSDR().data
    columnCount = self.getNumColumns()
    activityType = "Union SDR Activity"
    return self.mmGetCellTracePlot(unionSDRTrace, columnCount, activityType,
                                   title=title, showReset=showReset,
                                   resetShading=resetShading)