code: function (matrix4x4) {
      let ismirror = matrix4x4.isMirroring()
          // get two vectors in the plane:
      let r = this.normal.randomNonParallelVector()
      let u = this.normal.cross(r)
      let v = this.normal.cross(u)
          // get 3 points in the plane:
      let point1 = this.normal.times(this.w)
      let point2 = point1.plus(u)
      let point3 = point1.plus(v)
          // transform the points:
      point1 = point1.multiply4x4(matrix4x4)
      point2 = point2.multiply4x4(matrix4x4)
      point3 = point3.multiply4x4(matrix4x4)
          // and create a new plane from the transformed points:
      let newplane = Plane.fromVector3Ds(point1, point2, point3)
      if (ismirror) {
              // the transform is mirroring
              // We should mirror the plane:
        newplane = newplane.flipped()
      }
      return newplane
    }
docs: CONVERTED TO V2