%YAML 1.1
---
!!seq [
  !!map {
    ? !!str "explicit key1"
    : !!str "explicit value",
  },
  !!map {
    ? !!str "explicit key2"
    : !!null "",
  },
  !!map {
    ? !!str "explicit key3"
    : !!null "",
  },
  !!map {
    ? !!str "simple key1"
    : !!str "explicit value",
  },
  !!map {
    ? !!str "simple key2"
    : !!null "",
  },
]