When you have some line of codes which do solve a common problem, you can use it more and more times then you should split it into a Helper class like you did. But remember that this method must be a common method for all class can use, not in case inheritance. For example, you have a supper class A, with method called run() and all child of it also using this method, then you must put it there not moving it into a helper class.
Another comment to your code, when you have split code to the helper function, remember that this function only do a very common function, it will not process any particular problems, you must make it as general as you can. All particular problems (if need for run helper) must pre-process then pass into helper function via it's arguments.
As I see in your code, the function 'doSomeThing()' after you split the helper, this function does not have any code you just call the helper, it will be not a good practice.
Your code should be like this: