code: func (v *Notebook) PrependPage(child IWidget, tabLabel IWidget) int {
  	cTabLabel := nullableWidget(tabLabel)
  	c := C.gtk_notebook_prepend_page(v.native(), child.toWidget(), cTabLabel)
  	return int(c)
  }
docs: // PrependPage() is a wrapper around gtk_notebook_prepend_page().