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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 _fetch_cdn_data(self):
 """Fetches the container's CDN data from the CDN service"""

        if self._cdn_enabled is FAULT:
            headers = self.manager.fetch_cdn_data(self)
        else:
            headers = {}
        # Set defaults in case not all headers are present.
        self._set_cdn_defaults()
        if not headers:
            # Not CDN enabled; return
            return
        else:
            self._cdn_enabled = True
        for key, value in headers.items():
            low_key = key.lower()
            if low_key == "x-cdn-uri":
                self._cdn_uri = value
            elif low_key == "x-ttl":
                self._cdn_ttl = int(value)
            elif low_key == "x-cdn-ssl-uri":
                self._cdn_ssl_uri = value
            elif low_key == "x-cdn-streaming-uri":
                self._cdn_streaming_uri = value
            elif low_key == "x-cdn-ios-uri":
                self._cdn_ios_uri = value
            elif low_key == "x-log-retention":
                self._cdn_log_retention = (value == "True")