the recursive method but in ruby

```
def depth_sum(nested_list)
depth = 1
depth_sum_helper(nested_list, depth)
end
def depth_sum_helper(nested_list, depth)
result = 0
nested_list.each do |ni|
if ni.is_integer
result += ni.get_integer * depth
else
sub_list = ni.get_list
result += depth_sum_helper sub_list, depth+1
end
end
result
end
```