expect: "idx0idx1idx2idx3"
nodes:
- ts: 1
content: "idx0"
to: 0/
- ts: 0
content: "idx1"
from: 1/
to: 2/
- ts: 2
content: "idx2"
from: 0/
to: 3/
- ts: 3
content: "idx3"
from: 2/