Insert @renderer into the gutter. If @renderer is yet unowned then gutter claims its ownership. Otherwise just increases renderer's reference count. @renderer cannot be already inserted to another gutter.
a gutter renderer (must inherit from #GtkSourceGutterRenderer).
the renderer position.
%TRUE if operation succeeded. Otherwise %FALSE.
3.0
See Implementation
Insert @renderer into the gutter. If @renderer is yet unowned then gutter claims its ownership. Otherwise just increases renderer's reference count. @renderer cannot be already inserted to another gutter.