[
  {
    "id": "$bucket example",
    "stage": "$bucket",
    "kind": "example",
    "pipeline": [
      {
        "$bucket": {
          "groupBy": "$price",
          "boundaries": [
            0,
            10,
            20
          ],
          "default": "other",
          "output": {
            "count": {
              "$sum": 1
            }
          }
        }
      }
    ],
    "input": [
      {
        "price": 3
      },
      {
        "price": 14
      },
      {
        "price": 30
      }
    ],
    "result": [
      {
        "_id": 0.0,
        "count": 1
      },
      {
        "_id": 10.0,
        "count": 1
      },
      {
        "_id": "other",
        "count": 1
      }
    ]
  },
  {
    "id": "$bucket empty input",
    "stage": "$bucket",
    "kind": "empty input",
    "pipeline": [
      {
        "$bucket": {
          "groupBy": "$price",
          "boundaries": [
            0,
            10,
            20
          ],
          "default": "other",
          "output": {
            "count": {
              "$sum": 1
            }
          }
        }
      }
    ],
    "input": [],
    "result": []
  },
  {
    "id": "$bucket invalid specification",
    "stage": "$bucket",
    "kind": "invalid specification",
    "pipeline": [
      {
        "$bucket": null
      }
    ],
    "input": [
      {
        "price": 3
      },
      {
        "price": 14
      },
      {
        "price": 30
      }
    ],
    "error": "IllegalArgumentException",
    "message": "$bucket stage requires an object"
  },
  {
    "id": "$bucket unmatched without default",
    "stage": "$bucket",
    "kind": "unmatched without default",
    "pipeline": [
      {
        "$bucket": {
          "groupBy": "$price",
          "boundaries": [
            0,
            10
          ]
        }
      }
    ],
    "input": [
      {
        "price": 20
      },
      {},
      {
        "price": null
      }
    ],
    "result": []
  }
]