title: Fragment communication - Fragment to fragment
body: <p>I need help on understanding how the following scenario works and how to achieve the result.</p>
  
  <p>I have a class called <code>ShoppingCart</code>. 
  It has a method called <code>addItemsToShoppingCartFromPreviousOrder</code>.
  Now I have a fragment called <code>PreviousOrderFragment</code> with <code>onCreateView</code> method which is using the <code>RecyclerView</code>. Its a list of previous orders. 
  I have multiple lists. Now I want to know how to call the <code>addItemsToShoppingCartFromPreviousOrder</code> method from <code>ShoppingCart</code> into my fragment.
  so that when the user clicks a list, it will add to the cart.</p>