title: Windows Form App - MVP Design Pattern best practice
body: <p>I just have started to use MVP design pattern on Windows Form Application.
  I have structured my code into 3 folders (Model, View, Presenter), and I have managed to build my UI so far.</p>
  
  <p>What I'm trying to do now is to add some new classes, which will help me to do some operations (recording input sound, work with xlsx files, etc...). I don't know where to put these classes. I should think to implement them using MVP? Or I should make another folder, Common for eg., and I should put there all additional classes that I use?</p>
  
  <p>Is this a good practice?</p>