{
  "columns": [
    "invoice$customerId",
    "sum(lineAmount) as amount"
  ],
  "slice": [
    {
      "field": "invoice$invoiceDate",
      "op": "[)",
      "value": [
        "2012-01-01",
        "2013-01-01"
      ]
    }
  ],
  "groupBy": [
    "invoice$customerId"
  ],
  "orderBy": [
    "-amount",
    "invoice$customerId"
  ],
  "limit": 3,
  "returnTotal": true,
  "start": 0
}