def __init__(self, request, *args, **kwargs):
get = request.GET.copy()
self.chart_row = get.pop('chart_row', [None])[0]
self.chart_col = get.pop('chart_col', [None])[0]
self.chart_var = get.pop('chart_var', [None])[0]
self.chart_measure = get.pop('chart_measure', [None])[0]
request.GET = get
ChangeList.__init__(self, request, *args, **kwargs)
