code: def _get_sample_matrix():
      return csr_matrix(
          (np.random.random((10, 10)) > 0.5).astype(np.float64)
      )
  
file_path: implicit/tests/evaluation_test.py
imports: import numpy
  import pytest
  from scipy.sparse import csr_matrix, random
  import implicit
  from implicit.evaluation import leave_k_out_split, precision_at_k, train_test_split
  from implicit.datasets.movielens import get_movielens
label_desc: Use image node_id 1 for calling a global function with example usage: _get_sample_matrix() and returns: csr_matrix