the paper name
the human-readable name
the paper width, in units of @unit
the paper height, in units of @unit
the unit for @width and @height. not %GTK_UNIT_NONE.
a new GtkPaperSize object, use [method@Gtk.PaperSize.free] to free it
ConstructionException GTK+ fails to create the object.
Creates a new GtkPaperSize object with the given parameters.