Selects a range of characters in the label, if the label is selectable.
See gtk.label.Label.setSelectable. If the label is not selectable,
this function has no effect. If start_offset or
end_offset are -1, then the end of the label will be substituted.
Selects a range of characters in the label, if the label is selectable.
See gtk.label.Label.setSelectable. If the label is not selectable, this function has no effect. If start_offset or end_offset are -1, then the end of the label will be substituted.