code: def ascharacter():
      h2oframe = h2o.import_file(
          path=pyunit_utils.locate("smalldata/junit/cars.csv")
      )
      h2oframe.show()
      h2oframe["cylinders"] = h2oframe["cylinders"].asfactor()
      h2oframe["cylinders"].ascharacter()
      assert h2oframe["cylinders"].isfactor()[
          0
      ], "expected the column be a factor"
      assert not h2oframe["cylinders"].isstring()[
          0
      ], "expected the column to not be a string"
  
label_desc: Use image node_id 1 for calling a global function with example usage: ascharacter() without return types