def power_on(self, timeout_sec=TIMEOUT_SEC):
<EOL>self._powered_on.clear()<EOL>IOBluetoothPreferenceSetControllerPowerState(<NUM_LIT:1>)<EOL>if not self._powered_on.wait(timeout_sec):<EOL><INDENT>raise RuntimeError('<STR_LIT>')<EOL><DEDENT>
Power on Bluetooth.