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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def setup_filter(self, ):
 """Create a checkbox for every reftrack type so one can filter them :returns: None :rtype: None :raises: None """

        types = self.refobjinter.types.keys()
        for i, t in enumerate(types):
            cb = QtGui.QCheckBox("%s" % t)
            cb.setChecked(True)
            cb.toggled.connect(self.update_filter)
            self.typecbmap[t] = cb
            self.typefilter_grid.addWidget(cb, int(i / 4), i % 4)