code: def test_determine_num_threads():
      # 0 should raise an error
      assert_raises(ValueError, determine_num_threads, 0)
  
      # A string should raise an error
      assert_raises(TypeError, determine_num_threads, "1")
  
      # 1 should be 1
      assert_equal(determine_num_threads(1), 1)
  
      # A positive integer should not change
      assert_equal(determine_num_threads(4), 4)
  
      # A big negative number should be 1
      assert_equal(determine_num_threads(-10000), 1)
  
      # -2 should be one less than -1 (if there are more than 1 cores)
      if determine_num_threads(-1) > 1:
          assert_equal(
              determine_num_threads(-1), determine_num_threads(-2) + 1
          )
  
file_path: dipy/dipy/utils/tests/test_omp.py
imports: import os
  from dipy.utils.omp import cpu_count, thread_count, default_threads, _set_omp_threads, _restore_omp_threads, have_openmp, determine_num_threads
  import pytest
  from dipy.utils.parallel import has_ray, has_joblib
  from numpy.testing import assert_equal, assert_raises
label_desc: Use image node_id 3 for calling a global function with example usage: test_determine_num_threads() without return types