ng: 121.50657363869442, lat: 31.227646614453125 },
        { lng: 121.52418391477424, lat: 31.25831768661698 },
        { lng: 121.51534816216447, lat: 31.238932318412797 },
        { lng: 121.47411195956543, lat: 31.23653254767207 },
        { lng: 121.4948618756933, lat: 31.22694576870397 },
        { lng: 121.49695060106232, lat: 31.275195479192174 },
      ]
      let doublePositions = [...positions, ...positions]
      doublePositions.forEach((item) => {
        let line = new DC.FlowLinePrimitive(
   