where is the code transform intervals to the segments

[轨迹]

hi
   as scan query json shown below
  {
"queryType": "scan", "dataSource": "wikipedia", "resultFormat": "list",
"columns":[], "intervals": [ "2013-01-01/2013-01-02" ], "batchSize":20480,
"limit":3 }
 how does druid transform the parameter intervals to the intervals related
segments message, I cannot find the related code in druid project.