I don’t understand this code, the exercise is to:

Write a Python program to get all possible unique subsets from a set of distinct integers

```
class py_solution:
def sub_sets(self, sset):
return self.subsetsRecur([], sorted(sset))
def subsetsRecur(self, current, sset):
if sset:
return self.subsetsRecur(current, sset[1:]) + self.subsetsRecur(current + [sset[0]], sset[1:])
return [current]
print(py_solution().sub_sets([4,5,6]))
```

Thanks