[Changed the interface of momonga.get_historical_cumulative_energy_2()](https://github.com/nbtk/momonga/commit/9b874c6d01d3ecc81f4175e9fc79e3490ed811c6)
[Changed the interface of momonga.get_cumulative_energy_measured_at_fixed_time()](https://github.com/nbtk/momonga/commit/1bcb45ed1bdffdf972a6dcb188c916a669e94359)