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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 proxy_route_request(self, url, environ):
 """ Return the full url that this proxy request will be routed to The 'environ' PATH_INFO and REQUEST_URI will be modified based on the returned url Default is to use the 'proxy_prefix' to point to the proxy collection """

        if self.proxy_default_timestamp:
            environ['pywb_proxy_default_timestamp'] = self.proxy_default_timestamp

        return self.proxy_prefix + url