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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 get_formset_class(self, **kwargs):
 """ Returns the formset for the queryset, if a form class is available. """

        form_class = self.get_formset_form_class()
        if form_class:
            kwargs['formfield_callback'] = self.formfield_for_dbfield
            return model_forms.modelformset_factory(self.model,
                        form_class, fields=self.change_fields, extra=0,
                        **kwargs)