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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 enqueue_zonefile(self, zonefile_hash, block_height):
 """ Called when we discover a zone file. Queues up a request to reprocess this name's zone files' subdomains. zonefile_hash is the hash of the zonefile. block_height is the minimium block height at which this zone file occurs. This gets called by: * AtlasZonefileCrawler (as it's "store_zonefile" callback). * rpc_put_zonefiles() """

        with self.serialized_enqueue_zonefile:
            log.debug("Append {} from {}".format(zonefile_hash, block_height))
            queuedb_append(self.subdomain_queue_path, "zonefiles", zonefile_hash, json.dumps({'zonefile_hash': zonefile_hash, 'block_height': block_height}))