code: def test_mutate(step: BaseStep):
      dact = DACT(di=[0])
      cx = CX()
      with pytest.raises(AssertionError):
          step.handle_transform(dact, cx)
  
      step = step.mutate(
          new_method="transform_a", method_to_assign_to="transform"
      )
      _a = step.handle_transform(dact, cx).di
      assert _a == ["a"]
  
      step = step.mutate(
          new_method="transform_b", method_to_assign_to="transform"
      )
      _b = step.handle_transform(dact, cx).di
      assert _b == ["b"]
  
imports: import pytest
  from neuraxle.base import BaseStep
  from neuraxle.base import ExecutionContext
  from neuraxle.base import Identity, NonFittableMixin
  from neuraxle.data_container import DataContainer
  from neuraxle.hyperparams.space import HyperparameterSamples
  from neuraxle.pipeline import Pipeline
  from neuraxle.steps.flow import OptionalStep
  from neuraxle.steps.numpy import MultiplyByN
  from neuraxle.steps.output_handlers import OutputTransformerWrapper
label_desc: Use image node_id 9 for calling a global function with example usage: test_mutate(step) without return types