code: def test_round_to_nearest_half(dataframe):
      """Checks output for rounding to the nearest 1/2."""
      df = dataframe.round_to_fraction("Bell__Chart", 2)
      assert df.iloc[0, 1] == 1.0
      assert df.iloc[1, 1] == 2.5
      assert df.iloc[2, 1] == 3.0
      assert df.iloc[3, 1] == 1.0
      assert df.iloc[4, 1] == 2.5
      assert df.iloc[5, 1] == 3.0
      assert df.iloc[6, 1] == 1.0
      assert df.iloc[7, 1] == 2.5
      assert df.iloc[8, 1] == 3.0
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_round_to_nearest_half(dataframe) without return types