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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 _view_filter(self):
 """ Overrides OsidSession._view_filter to add sequestering filter. """

        view_filter = OsidSession._view_filter(self)
        if self._sequestered_view == SEQUESTERED:
            view_filter['sequestered'] = False
        return view_filter