def set_remote_update(self, payload: dict) -> None:
        """Save the ChannelUpdate message for the incoming direction of this channel.
        This message contains info we need to populate private route hints when
        creating invoices.
        """
        assert payload['short_channel_id'] in [self.short_channel_id, self.get_local_scid_alias()]
        from .channel_db import ChannelDB
        ChannelDB.verify_channel_update(payload, start_node=self.node_id)
        raw = payload['raw']
        self.storage['remote_update'] = raw.hex()
Save the ChannelUpdate message for the incoming direction of this channel.
        This message contains info we need to populate private route hints when
        creating invoices.
        
electrum/lnchannel.py