code: def test_predict_from_operation_invalid_operator():
      with pytest.raises(ValueError, match="Unrecognized operator: ="):
          ThresholdOperation("=", 0.5)
  
imports: import pytest
  from fairlearn.postprocessing._threshold_operation import ThresholdOperation
label_desc: Use image node_id 3 for calling a global function with example usage: test_predict_from_operation_invalid_operator() without return types