Can't omit arrows

[ijhoskins]

In the docs:

arrow.gap The gap distance between intermittent arrows. Default: NULL. Set arrow.num and arrow.gap to NULL to suppress intermittent arrows

However, if I set arrow.num and arrow.gap to NULL, I get the following error:

Error in ggplot_add.transcript(object, p, objectname): Please provide either arrow.num or arrow.gap!
Traceback:

1. `+.gg`(cov_gg + labs(title = fusion_name), geom_transcript(gtf.gr = trx_id_gr, 
 .     gene.name = gene_name, plot.height = 0.2, arrow.num = NULL, 
 .     arrow.gap = NULL))
2. add_ggplot(e1, e2, e2name)
3. ggplot_add(object, p, objectname)
4. ggplot_add.transcript(object, p, objectname)
5. stop("Please provide either arrow.num or arrow.gap!")
6. .handleSimpleError(function (cnd) 
 . {
 .     watcher$capture_plot_and_output()
 .     cnd <- sanitize_call(cnd)
 .     watcher$push(cnd)
 .     switch(on_error, continue = invokeRestart("eval_continue"), 
 .         stop = invokeRestart("eval_stop"), error = invokeRestart("eval_error", 
 .             cnd))
 . }, "Please provide either arrow.num or arrow.gap!", base::quote(ggplot_add.transcript(object, 
 .     p, objectname)))