{
    head:{
        type:"APACHE_DRILL_PHYSICAL",
        version:"1",
        generator:{
            type:"manual"
        }
    },
    graph:[
        {
            @id: 1,
            pop:"mock-sub-scan",
            url: "http://apache.org",
            entries:[
                {records: 1, types: [
                  {name: "intColumn", type: "INT", mode: "REQUIRED"},
                  {name: "bigIntColumn", type: "BIGINT", mode: "REQUIRED"},
                  {name: "float4Column", type: "FLOAT4", mode: "REQUIRED"},
                  {name: "float8Column", type: "FLOAT8", mode: "REQUIRED"},
                  {name: "intNullableColumn", type: "INT", mode: "OPTIONAL"},
                  {name: "bigIntNullableColumn", type: "BIGINT", mode: "OPTIONAL"},
                  {name: "float4NullableColumn", type: "FLOAT4", mode: "OPTIONAL"},
                  {name: "float8NullableColumn", type: "FLOAT8", mode: "OPTIONAL"}
                ]}
            ]
        },
        {
            @id:2,
            child: 1,
        pop:"project",
            exprs: [
                  { ref: "NullIntAddInt", expr:"intNullableColumn + intColumn" },
                  { ref: "IntAddNullInt", expr:"intColumn + intNullableColumn  " },
                  { ref: "IntAddNullFloat4", expr:"intColumn + float4NullableColumn  " },
                  { ref: "Float4AddNullInt", expr:"float4Column  + intNullableColumn  " },
                  { ref: "Float8AddNullBigInt", expr:"float8Column  + bigIntNullableColumn  " }
           ]
        },
        {
            @id: 3,
            child: 2,
            pop: "screen"
        }
    ]
}