class_docstr: Transform method is automatically implemented as returning data inputs as it is.
  Please make your steps inherit from NonTransformableMixin, when they don't need any transformations.
  Also, make sure that BaseStep is the last step you inherit from.
code: def fit(
      self, data_inputs, expected_outputs=None
  ) -> "NonTransformableStep":
      # insert your fit code here
      print("NonTransformableStep: I fitted.")
      return self
  
file_path: Neuraxle/examples/getting_started/plot_non_fittable_mixin.py
imports: import numpy
  from neuraxle.base import NonTransformableMixin, Identity, BaseStep, NonFittableMixin
  from neuraxle.pipeline import Pipeline
label_desc: Use image node_id 2 for calling the NonTransformableStep obj's underlying member method code with example usage: obj.fit(data_inputs, expected_outputs) and returns: self