code: def test_computed_y_column():
      p = (
          ggplot(data, aes("x"))
          + stat_ecdf(size=2)
          # Should be able to use calculated & create a new column called y
          + stat_ecdf(
              aes(y=after_stat("ecdf-0.2")), size=2, color="blue"
          )
      )
      assert p == "computed_y_column"
  
imports: import pandas
  from plotnine import aes, after_stat, ggplot, stat_ecdf
label_desc: Use image node_id 3 for calling a global function with example usage: test_computed_y_column() without return types