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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _step(self) -> typing.Union[None, 'projects.ProjectStep']: """ Internal access to the source step. Should not be used outside of Cauldron development. :return: The ProjectStep instance that this ExposedStep represents """

        import cauldron
        try:
            return cauldron.project.get_internal_project().current_step
        except Exception:
            return None