Describe extensions_tabline.vim

  It should use a tabline
    e! file1
    Assert Match(airline#extensions#tabline#get(), '%#airline_tabsel# %(%{airline#extensions#tabline#get_buffer_name(\d)}%) |%=%#airline_tabfill_to_airline_tabfill#%#airline_tabfill# buffers' )
  End

  It Trigger on BufDelete autocommands
    e! file1
    sp file2
    bd
    Assert Match(airline#extensions#tabline#get(), '%#airline_tabsel# %(%{airline#extensions#tabline#get_buffer_name(\d)}%) |%=%#airline_tabfill_to_airline_tabfill#%#airline_tabfill# buffers' )
  End
End
