stages:
  - id: stage-1
    title: Foundations
    concepts: [a, bottleneck]
  - id: stage-2
    title: Advanced Analysis
    concepts: [b, d1]
  - id: stage-3
    title: Methods
    concepts: [c, d2, d3]
  - id: stage-4
    title: Detached Topic
    concepts: [isolated]