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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 add_response_headers(self, headers, **overrides):
 """Adds the specified response headers while keeping existing ones in-tact"""

        response_headers = self.route.get('response_headers', {}).copy()
        response_headers.update(headers)
        return self.where(response_headers=response_headers, **overrides)