Insert a page into this at the given position.
| this |
a Notebook |
| child |
the Widget to use as the contents of the page |
| tab_label |
the Widget to be used as the label for the page, or null to use the default label, “page N” |
| position |
the index (starting at 0) at which to insert the page, or -1 to append the page after all other pages |
|
the index (starting from 0) of the inserted page in the notebook, or -1 if function fails |