title: Python, how to set image to ttk.notebook tab
body: <p>How to set image on <code>tab</code> in <strong>ttk.notebook</strong> tabs ? </p>
  
  <p>The following code isn't working, the image doesn't appear:</p>
  
  <pre><code>import tkinter as tk
  from tkinter import ttk
  
  class Tab(tk.Frame):
      def __init__(self, master, *args, **kwargs):
          super().__init__(master, *args, **kwargs)
          self.label = tk.Label(self, text='Blablablee')
          self.label.pack()
  
  root = tk.Tk()
  notebook = ttk.Notebook(root)
  notebook.pack()
  notebook.add(Tab(notebook), 
               text='Tab1', 
               image=tk.PhotoImage(file='icon.png'), 
               compound='left')
  root.mainloop()
  </code></pre>