{
  head : {
    version : 1,
    generator : {
      type : "optiq",
      info : "na"
    },
    type : "APACHE_DRILL_PHYSICAL"
  },
         graph:[
         {
             @id:1,
             pop:"mock-sub-scan",
             url: "http://apache.org",
             entries:[
                 {records: 1, types: [
                   {name: "blue", type: "BIGINT", mode: "REQUIRED"}
                 ]}
             ]
         }, {
    pop : "project",
    @id : 2,
    exprs : [
    { ref : "ref1", expr : " lshift(3,10) "},
    { ref : "ref2", expr : " rshift(3072, 10) "},
    { ref : "ref3", expr : " xor(7, 9) " }
    ],
    child : 1
  }, {
    pop : "screen",
    @id : 3,
    child : 2
  } ]
}