docs: public static SVGPath drawFakeVoronoi(Projection2D proj, List<double[]> means) {
      CanvasSize viewport = proj.estimateViewport();
      final SVGPath path = new SVGPath();
      // Difference
      final double[] dirv = VMath.minus(means.get(1), means.get(0));
      VMath.rotate90Equals(dirv);
      double[] dir = proj.fastProjectRelativeDataToRenderSpace(dirv);
      // Mean
      final double[] mean = VMath.plus(means.get(0), means.get(1));
      VMath.timesEquals(mean, 0.5);
      double[] projmean = proj.fastProjectDataToRenderSpace(mean);
  
      double factor = viewport.continueToMargin(projmean, dir);
      path.moveTo(projmean[0] + factor * dir[0], projmean[1] + factor * dir[1]);
      // Inverse direction:
      dir[0] *= -1;
      dir[1] *= -1;
      factor = viewport.continueToMargin(projmean, dir);
      path.drawTo(projmean[0] + factor * dir[0], projmean[1] + factor * dir[1]);
      return path;
    }