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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 options(self, request, *args, **kwargs):
 """ Implements a OPTIONS HTTP method function returning all allowed HTTP methods. """

        allow = []
        for method in self.http_method_names:
            if hasattr(self, method):
                allow.append(method.upper())
        r = self.render_to_response(None)
        r['Allow'] = ','.join(allow)
        return r