code: def test_check_safe_k_value(safe_k):
      X = np.random.rand(10, 2)
      y = np.ones(10)
      with pytest.raises(ValueError):
          ds_test = BaseDS(safe_k=safe_k)
          ds_test.fit(X, y)
  
imports: import unittest.mock
  from unittest.mock import Mock, MagicMock
  import numpy
  import pytest
  from sklearn.exceptions import NotFittedError
  from sklearn.neighbors import KNeighborsClassifier
  from deslib.base import BaseDS
  from deslib.util.dfp import frienemy_pruning_preprocessed
  from .conftest import create_base_classifier
label_desc: Use image node_id 7 for calling a global function with example usage: test_check_safe_k_value(safe_k) without return types