sidebarPosition 
  The sidebar position.
If it's set to GTK_PACK_START, the sidebar is displayed before the content, if GTK_PACK_END, it's displayed after the content.
Since
1.4
The sidebar position.
If it's set to GTK_PACK_START, the sidebar is displayed before the content, if GTK_PACK_END, it's displayed after the content.
1.4