{
  head:
    {
      type: "APACHE_DRILL_PHYSICAL",
      version: 1,
      generator:
        {
          type: "manual"
        }
    },
  graph:
    [
      {
        @id: 1,
        pop: "parquet-scan",
        entries:
          [
            {
              path: "./sample-data/region.parquet"
            }
          ],
        storageengine:
          {
            "type": "parquet",
            "dfsName": "file:///"
          }
      },
      {
        @id: 2,
        child: 1,
        pop: "union-exchange"
      },
      {
        @id: 3,
        child: 2,
        pop: "screen"
      } 
    ]
}