200                  << loghex(connection_id);  in OnServiceSearchComplete()
230       LOG(INFO) << __func__ << ": unknown conn_id=" << loghex(conn_id);  in OnCharacteristicValueChanged()
250     LOG(ERROR) << __func__ << ": unknown handle=" << loghex(handle);  in OnCharacteristicValueChanged()
255     LOG(INFO) << __func__ << ": handle=" << loghex(handle);  in OnNotificationEvent()
268       LOG(INFO) << __func__ << ": malformed len=" << loghex(len);  in OnVolumeControlStateChanged()
278     LOG(INFO) << __func__ << "volume " << loghex(device->volume) << "mute"  in OnVolumeControlStateChanged()
279               << loghex(device->mute) << "change_counter"  in OnVolumeControlStateChanged()
280               << loghex(device->change_counter);  in OnVolumeControlStateChanged()
293     LOG(INFO) << __func__ << "flags " << loghex(device->flags);  in OnVolumeControlFlagsChanged()
302                 << "unknown connection_id=" << loghex(connection_id);  in OnGattWriteCcc()
309                  << "Failed to register for notification: " << loghex(handle)  in OnGattWriteCcc()
316               << "Successfully register for indications: " << loghex(handle);  in OnGattWriteCcc()
354                  << loghex(connection_id);  in OnGattDisconnected()
378                  << loghex(connection_id);  in OnWriteControlResponse()
382     LOG(INFO) << "Write response handle: " << loghex(handle)  in OnWriteControlResponse()
383               << " status: " << loghex((int)(status));  in OnWriteControlResponse()