mutation AppendCommandRunOutput($jobId: ID!, $attemptId: ID!, $chunks: [CommandRunOutputInput!]!) {
  appendCommandRunOutput(jobId: $jobId, attemptId: $attemptId, chunks: $chunks) {
    id
    attemptId
    attemptNumber
    sequence
    stream
    dataBase64
  }
}

{
  "jobId": "id",
  "attemptId": "id",
  "chunks": [
    {
      "sequence": 1,
      "stream": "STDOUT",
      "dataBase64": "string",
      "byteLength": 1,
      "createdAt": "string"
    }
  ]
}

{
  "data": {
    "appendCommandRunOutput": [
      {
        "id": "id",
        "attemptId": "id",
        "attemptNumber": 1,
        "sequence": 1,
        "stream": "STDOUT",
        "dataBase64": "string"
      }
    ]
  }
}