code: def test_watermark():
      data = pd.DataFrame({"x": [1, 2, 3], "y": [1, 2, 3]})
  
      p = (
          ggplot(data)
          + geom_point(aes("x", "y"))
          + watermark(wm_file, 150, 160)
          + watermark(wm_file, 150, 210, 0.5)
      )
  
      assert p == "watermark"
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_watermark() without return types