code: def test_x_dataset(x_dataset_regressor):
      dataset = xgb.DMatrix(x_dataset_regressor)
      assert dataset.num_row() == 20, "Number of rows should be 20"
      assert (
          dataset.num_col() == 6
      ), "Number of columns/features should be 6"
  
file_path: dtreeviz/testing/testlib/models/test_decision_tree_xgb_regressor.py
imports: import joblib
  import numpy
  import pytest
  import xgboost
  from dtreeviz.models.xgb_decision_tree import ShadowXGBDTree
label_desc: Use image node_id 3 for calling a global function with example usage: test_x_dataset(x_dataset_regressor) without return types