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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 _gc_dead_sinks(self):
 """ Remove any dead weakrefs. """

        deadsinks = []
        for i in self._sinks:
            if i() is None:
                deadsinks.append(i)
        for i in deadsinks:
            self._sinks.remove(i)