Sequence of Sequences

my\_sequences:
  - [1, 2, 3]
  - [4, 5, 6]
  -  
    - 7
    - 8
    - 9
    - 0 

#↓ Equivalent JSON

{
  "my\_sequences": [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9, 0]
  ]
}