nodes:
  - id: op_1
    operator:
      python: op_1/op_1.py
      inputs:
        tick: dora/timer/millis/100
      outputs:
        - some-output
  - id: op_2
    operator:
      python: op_2/op_2.py
      inputs:
        tick: dora/timer/secs/2
      outputs:
        - some-output

  - id: custom-node_1
    custom:
      source: ./node_1/node_1.py
      inputs:
        tick: dora/timer/secs/1
        input-1: op_1/some-output
        input-2: op_2/some-output