▽
└─◨ Attr presence: foo
  ┠─◉ Push element: +
  ┃ └─◨ Attr presence: bar
  ┃   ┠─◉ Push element: >
  ┃   ┃ └─◨ Attr presence: baz
  ┃   ┃   ┖─◁ #2 [0,3,0] value 3
  ┃   ┖─◁ #1 [0,2,0] value 2
  ┖─◁ #0 [0,1,0] value 1