insertPage
Insert a page into @notebook at the given position.
Return
the index (starting from 0) of the inserted page in the notebook, or -1 if function fails
Parameters
child
the GtkWidget to use as the contents of the page
tabLabel
the GtkWidget 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