Gtk.TextBuffer.prototype.insert_range

function insert_range(iter:Gtk.TextIter, start:Gtk.TextIter, end:Gtk.TextIter):void {
    // Gjs wrapper for gtk_text_buffer_insert_range()
}

Copies text, tags, and pixbufs between start and end (the order of start and end doesn't matter) and inserts the copy at iter. Used instead of simply getting/inserting text because it preserves images and tags. If start and end are in a different buffer from buffer, the two buffers must share the same tag table.

Implemented via emissions of the insert_text and apply_tag signals, so expect those.