Before (Define functions):
  " change the syntax using a temporary wiki
  function! SetSyntax(vw_syn)
    if a:vw_syn ==# 'default'
      let ext = 'wiki'
    elseif a:vw_syn ==# 'markdown'
      let ext = 'md'
    elseif a:vw_syn ==# 'media'
      let ext = 'mw'
    else
      Log 'ERROR: Invalid syntax "' . a:vw_syn . '" in SetSyntax()'
      Log 'NOTE: function only accepts "media" for setting mediawiki syntax'
      return
    endif
    let path = expand('%:p:h')
    let new_temp_wiki_settings = {'path': path,
          \ 'ext': ext,
          \ 'syntax': a:vw_syn,
          \ }

    " Remove any temporary wikis each time this function is called.
    " This is necessary to ensure syntax is properly set when running multiple tests
    " NOTE: this assumes there are 3 defined wikis in the vimrc. The last wiki
    " contains default settings for temporary wikis (so there are always
    " num wikis in vimrc + 1)
    let num_wikis = len(g:vimwiki_wikilocal_vars)
    while  num_wikis > 4
      call remove(g:vimwiki_wikilocal_vars, num_wikis - 1)
      let num_wikis = num_wikis - 1
    endwhile

    " add the new wiki
    call vimwiki#vars#add_temporary_wiki(new_temp_wiki_settings)
    call vimwiki#vars#set_bufferlocal('wiki_nr', 3)

    " verify syntax was set correctly
    Assert vimwiki#vars#get_wikilocal('syntax') ==# a:vw_syn, 'ERROR: Vimwiki syntax not set correctly.'
  endfunction

  " reload plugin to change settings
  function! ReloadVimwiki()
    " clear mappings so plugin can be reloaded
    " this is needed if running manually multiple times
    nmapclear

    unlet g:loaded_vimwiki
    source plugin/vimwiki.vim
  endfunction