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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 delete(self):
 """ Delete all statements matching the current context identifier from the main store. """

        if self.parent.buffered:
            query = 'CLEAR SILENT GRAPH %s ;' % self.identifier.n3()
            self.parent.graph.update(query)
            self.flush()
        else:
            self.graph.remove((None, None, None))