The integer for the index starting from 0 of the added page in the
    notebook, or -1 if the function fails.  
                  Inserts a page into the notebook depending on the value of the 
pos    keyword argument with the 
:end default value:    
    - :start
 - 
      Prepends a page to the notebook. This replaces the functions:      
        - gtk_notebook_prepend_page()
         - gtk_notebook_prepend_page_menu()
       
          - :end
 - 
      Appends a page to the notebook. This replaces the functions:      
        - gtk_notebook_append_page()
         - gtk_notebook_append_page_menu()
       
          - otherwise
 -       Insert a page into the notebook at the given pos, which is an
      integer for the index starting from 0. This replaces the functions:      
        - gtk_notebook_insert_page()
         - gtk_notebook_insert_page_menu()
       
        
  If the 
menu optional argument is 
nil, that is the default value,  and the 
tab argument is a 
gtk:label widget or 
nil, then  the menu label will be a newly created label with the same text as 
tab.  If the 
tab argument is not a 
gtk:label widget, the 
menu
  argument must be specified if the page-switch menu is to be used.