Command to disable WiFi to save power

There should be an easy command to save power by disabling the WiFi. Normally the ESP-01 consumes about 0.07A but it should be possible to bring power consumption significantly down to 0.01-0.02A by going to "Modem-Sleep" (as it is called by the manual). In "Modem-Sleep", CPU and other peripherals are still running, so the sketch should be able to continue running as usual.