---
- name: Empty flow collections
  from: '@perlpunk'
  tags: flow mapping sequence
  yaml: |
    ---
    nested sequences:
    - - - []
    - - - {}
    key1: []
    key2: {}
  tree: |
    +STR
     +DOC ---
      +MAP
       =VAL :nested sequences
       +SEQ
        +SEQ
         +SEQ
          +SEQ []
          -SEQ
         -SEQ
        -SEQ
        +SEQ
         +SEQ
          +MAP {}
          -MAP
         -SEQ
        -SEQ
       -SEQ
       =VAL :key1
       +SEQ []
       -SEQ
       =VAL :key2
       +MAP {}
       -MAP
      -MAP
     -DOC
    -STR
  json: |
    {
      "nested sequences": [
        [
          [
            []
          ]
        ],
        [
          [
            {}
          ]
        ]
      ],
      "key1": [],
      "key2": {}
    }
  dump: |
    ---
    nested sequences:
    - - - []
    - - - {}
    key1: []
    key2: {}