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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_etags_and_matchers(self, request):
 """Get the etags from the header and perform a validation against the required preconditions."""

        # evaluate the preconditions, raises 428 if condition is not met
        self.evaluate_preconditions(request)
        # alright, headers are present, extract the values and match the conditions
        return super(APIETAGProcessor, self).get_etags_and_matchers(request)