code: def toupper_tolower_check():
      # Connect to a pre-existing cluster
  
      frame = h2o.import_file(
          path=pyunit_utils.locate("smalldata/iris/iris.csv"),
          col_types=[
              "numeric",
              "numeric",
              "numeric",
              "numeric",
              "string",
          ],
      )
  
      # single column (frame)
      frame["C5"] = frame["C5"].toupper()
      assert (
          frame[0, 4] == "IRIS-SETOSA"
      ), "Expected 'IRIS-SETOSA', but got {0}".format(frame[0, 4])
  
      # single column (vec)
      vec = frame["C5"]
      vec = vec.toupper()
      assert (
          vec[2, 0] == "IRIS-SETOSA"
      ), "Expected 'IRIS-SETOSA', but got {0}".format(vec[2, 0])
  
      vec = vec.tolower()
      assert (
          vec[3, 0] == "iris-setosa"
      ), "Expected 'iris-setosa', but got {0}".format(vec[3, 0])
  
label_desc: Use image node_id 1 for calling a global function with example usage: toupper_tolower_check() without return types