code: def setup_tree(self):
          
          self.tree.insert("", tk.END, text="Example 1", iid="1")
          self.tree.insert("", tk.END, text="Example 2", iid="2")
          self.tree.insert("2", tk.END, text="Example Child")
          self.tree.heading("#0", text="Example heading")
docs: Setup an example Treeview