code: def test_valid_diff_threshold_value(
      diff_thresh, create_pool_classifiers
  ):
      X = np.random.rand(10, 2)
      y = np.ones(10)
      with pytest.raises(ValueError):
          dcs = BaseDCS(
              create_pool_classifiers,
              selection_method="diff",
              diff_thresh=diff_thresh,
          )
          dcs.fit(X, y)
  
imports: from unittest.mock import MagicMock
  import numpy
  import pytest
  from deslib.dcs.base import BaseDCS
label_desc: Use image node_id 4 for calling a global function with example usage: test_valid_diff_threshold_value(diff_thresh, create_pool_classifiers) without return types