code: def test_stackdir_down():
      p = ggplot(data, aes("x")) + geom_dotplot(
          bins=15, stackdir="down"
      )
  
      assert p == "stackdir_down"
  
file_path: plotnine/tests/test_geom_dotplot.py
imports: import pandas
  from plotnine import aes, geom_dotplot, ggplot
label_desc: Use image node_id 5 for calling a global function with example usage: test_stackdir_down() without return types