code: def test_hull():
      p = (
          ggplot(mtcars)
          + aes("wt", "mpg", color="factor(cyl)")
          + geom_point()
          + stat_hull(size=1)
      )
  
      assert p == "hull"
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_hull() without return types