title: Working with global variables in multiple classes and multiple modules
body: <p>If I create a global variable in a function in a class, how can I use that variable in another function in a different class?</p>
  
  <p>NB: Classes are found in different modules.</p>
  
  <p>Do I need to declare the global variables in the <strong>init</strong> function of each class?</p>