code: def test_categorical(self) -> None:
      self.run_categorical("approx")
  
file_path: xgboost/tests/python/test_plotting.py
imports: import json
  import numpy
  import pytest
  import xgboost
  from xgboost import testing
label_desc: Use image node_id 4 for calling the TestPlotting obj's underlying member method code with example usage: obj.test_categorical() without return types