GlSequenceRef new_gs(new GlSequence(gs));
new_gs->update_annotation_draw_function("gene", draw_narrow_track, default_color);
// mark where the sequence is
GlSequenceRef new_gs(new GlSequence(gs));
new_gs->update_annotation_draw_function("gene", draw_narrow_track, default_color);
// mark where the sequence is