fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
let key = format!("monitors/{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
let key = format!("monitors/{}_{}", funding_txo.txid.to_hex(), funding_txo.index);