%YAML 1.1
---
!!seq [
  !!map {
    ? !!str "sun"
    : !!str "yellow"
  },
  !!map {
    ? !!map {
      ? !!str "earth"
      : !!str "blue"
    }
    : !!map {
      ? !!str "moon"
      : !!str "white"
    }
  }
]