code: def test_csr(self):
      def verify_csr():
          indptr = np.array([0, 2, 3, 6])
          indices = np.array([0, 2, 2, 0, 1, 2])
          data = np.array([1, 2, 3, 4, 5, 6])
          X = scipy.sparse.csr_matrix(
              (data, indices, indptr), shape=(3, 3)
          )
          dtrain = xgb.DMatrix(X, data_split_mode=DataSplitMode.COL)
          assert dtrain.num_row() == 3
          assert dtrain.num_col() == 3 * xgb.collective.get_world_size()
  
      tm.run_with_rabit(world_size=3, test_fn=verify_csr)
  
imports: import csv
  import os
  import tempfile
  import warnings
  import numpy
  import pytest
  import scipy.sparse
  from hypothesis import given, settings, strategies
  from scipy.sparse import csr_matrix, rand
  import xgboost
  from xgboost import testing
  from xgboost.core import DataSplitMode
  from xgboost.testing.data import np_dtypes, run_base_margin_info
label_desc: Use image node_id 3 for calling the TestDMatrixColumnSplit obj's underlying member method code with example usage: obj.test_csr() without return types