code: def test_dmatrix_numpy_init_omp(self):
      rows = [1000, 11326, 15000]
      cols = 50
      for row in rows:
          X = np.random.randn(row, cols)
          y = np.random.randn(row).astype("f")
          dm = xgb.DMatrix(X, y, nthread=0)
          np.testing.assert_array_equal(dm.get_label(), y)
          assert dm.num_row() == row
          assert dm.num_col() == cols
  
          dm = xgb.DMatrix(X, y, nthread=10)
          np.testing.assert_array_equal(dm.get_label(), y)
          assert dm.num_row() == row
          assert dm.num_col() == cols
  
imports: import json
  import os
  import pathlib
  import tempfile
  from pathlib import Path
  import numpy
  import pytest
  import xgboost
  from xgboost import testing
label_desc: Use image node_id 9 for calling the TestBasic obj's underlying member method code with example usage: obj.test_dmatrix_numpy_init_omp() without return types