source: &source
  ADDR: 127.0.0.1

destination: &dest
  ADDR: 127.0.0.2

windows:
  - observer:
      layout: main-horizontal
      panes:
        - source:
          - <<: [ *source, *ssh_open ]
        - destination:
          - <<: [ *destination ]
          - <<: [ *ssh_open ]