---
direction: Horizontal
parts:
  - direction: Vertical
    split_size:
      Percent: 40
  - direction: Vertical
    parts:
      - direction: Horizontal
        split_size:
          Percent: 40
      - direction: Horizontal
        expansion_boundary: true
      - direction: Horizontal
        split_size:
          Percent: 40
  - direction: Vertical
    split_size:
      Percent: 40