Prepends a page to this.
| this |
a `GtkNotebook` |
| child |
the `GtkWidget` to use as the contents of the page |
| tab_label |
the `GtkWidget` to be used as the label for the page, or null to use the default label, “page N” |
|
the index (starting from 0) of the prepended page in the notebook, or -1 if function fails |