Maybe we could have some "constants" in the form on class variable:
```python
class Vm(object):
    SUSPEND = "suspend"
    ON = "on"
    OFF = "off"
    
    # Other content of the class ...
```

Then in this method it would look like this:
```python
if option == Vm.ON:  # or `is` but that would probably remove possibility of just passing "on" that could come from other place that constant
    # foo
```

And it would be called like this:
```python
some_vm.power_control_from_provider(Vm.ON)
# or 
some_vm.power_control_from_provider(some_vm.ON)  # To not have to import the class separately
```