---
key0: &id00
  zero:   0
key1: &id01
  <<: *id00
  subkey_a: asdf
  subkey_b: qwer
  Z:   "key1.Z"
key2: &id02
  everyday: apple
  X:   1
  Y:   2
  Z:   "key2.Z"
  A:
    - <<: *id00
      zero:  "00"
    - <<: *id01
    - <<: *id02   #cycle!
      everyday: shuffling
      Y:        3000
  <<:  *id00
key3: &id03
  <<: [*id01, *id02, *id01]
  subkey_a: foo
  subkey_c: bar
  deeper:
    challenger:   deep
    <<:           *id00