I am trying to use QHull.jl to estimate the volume of points in high dimensional space. Unfortunately, some of the results from simple 2D examples seem to be in correct.

Here is a MWE:

```
using Plots, QHull, Random
Random.seed!(3325)
points1 = rand(10000, 2)
# shift the second set of points up and to the right
points2 = rand(10000, 2) .+ .9
points3 = vcat(points1, points2)
hull = chull(points3)
# expected result 1 + 1 - .1^2 = 1.99
# obtained result ≈ 2.78
print(hull.volume)
scatter(points3[:,1], points3[:,2], leg=false, grid=false)
```

Here is the plot:

What is going wrong?