Before:
  Save &l:statusline

  let b:funky_command_created = 0

  " We will test for the existence of this command, so create one if needed.
  if !exists(':CtrlPFunky')
    command CtrlPFunky echo
    let b:funky_command_created = 1
  endif

After:
  if b:funky_command_created
    delcommand CtrlPFunky
    let b:funky_command_created = 0
  endif

  Restore

Execute(ALE shouldn't do much of anything for ctrlp-funky buffers):
  Assert !ale#ShouldDoNothing(bufnr('')), 'The preliminary check failed'

  let &l:statusline = '%#CtrlPMode2# prt %*%#CtrlPMode1# line %* <mru>={%#CtrlPMode1# funky %*}=<fil> <-> %=%<%#CtrlPMode2# %{getcwd()} %*'

  Assert ale#ShouldDoNothing(bufnr(''))