Before (Setup):
  let g:vimwiki_folding = 'expr:quick'

  " clear mappings so plugin can be reloaded
  " this is needed if running manually multiple times
  nmapclear

  " reload the plugin to set the fold method
  unlet g:loaded_vimwiki
  source plugin/vimwiki.vim

Execute (Expect < 0.5 second delay: Issue #580):
  " prep
  edit test/resources/delay.wiki
  normal! 50%
  normal! zozo
  tabedit

  " run test
  let start = reltime()
  tabprev
  redraw
  let end = str2float(reltimestr(reltime(start)))

  " cleanup
  bdelete test/resources/delay.wiki
  tabclose

  " verify
  Log 'Elapsed time = ' . string(end)
  Assert end < 0.5, 'Took longer than expected: ' . string(end) . ' seconds'