Execute ( SpaceVim api: unicode#box ):
  new
  let &encoding = 'utf-8'
  let box = SpaceVim#api#import('unicode#box')
  AssertEqual box.drawing_box([1,2,3] , 1, 3, 5),
    \ ['╭─────┬─────┬─────╮', '│  1  │  2  │  3  │', '╰─────┴─────┴─────╯']