获取采集的直线箭头数据问题请教

  function getPincerArrowValue() {
    var entityList = viewer.entities.values;
    console.log(entityList);
    for (var i = 0; i < entityList.length; i++) {
      var entity = entityList[i];
      console.log(entity.polygon.hierarchy.getValue());
      if (typeof (entity.valueFlag) != "undefined") {
        console.log("采集的钳击箭头(笛卡尔)：", entity.polygon.hierarchy.getValue().positions);
        var dke = entity.polygon.hierarchy.getValue().positions;
        var objArr = [];
        for (var i = 0; i < dke.length; i++) {
          var ellipsoid = viewer.scene.globe.ellipsoid;
          var cartesian3 = new cesium.Cartesian3(dke[i].x, dke[i].y, dke[i].z);
          var cartographic = ellipsoid.cartesianToCartographic(cartesian3);
          //console.log("cartographic",cartographic);
          var obj = {};
          obj.lat = toDegrees(cartographic.latitude);
          obj.lng = toDegrees(cartographic.longitude);
          //obj.alt=0;
          objArr.push(obj);
        }
        console.log("采集的钳击箭头(经纬度)", objArr);
        console.log("采集的钳击箭头关键点", entity.polygon.hierarchy.getValue().keyPoints);
      }

    }
  }

第二个console.log => null 问题 获取采集的直线箭头数据
报错：Cannot read properties of null (reading 'positions')

你这个是什么第三方 SDK 里的东西吧